Given is an integer S. Find how many sequences there are whose terms are all integers greater than or equal to 3, and whose sum is equal to S. The answer can be very large, so output it modulo 10^9 + 7.

Constraints

* 1 \leq S \leq 2000
* All values in input are integers.

Input

Input is given from Standard Input in the following format:


S


Output

Print the answer.

Examples

Input

7


Output

3


Input

2


Output

0


Input

1729


Output

294867501
import java.util.*;

class ModIntFactory {
    private final ModArithmetic ma;
    private final int mod;

    public ModIntFactory(int mod) {
        this.ma = ModArithmetic.of(mod);
        this.mod = mod;
    }

    public ModInt create(long value) {
        if ((value %= mod) < 0) value += mod;
        if (ma instanceof ModArithmetic.ModArithmeticMontgomery) {
            return new ModInt(((ModArithmetic.ModArithmeticMontgomery) ma).generate(value));
        }
        return new ModInt((int) value);
    }

    class ModInt {
        private int value;
        private ModInt(int value) {
            this.value = value;
        }
        public int mod() {
            return mod;
        }
        public int value() {
            if (ma instanceof ModArithmetic.ModArithmeticMontgomery) {
                return ((ModArithmetic.ModArithmeticMontgomery) ma).reduce(value);
            }
            return value;
        }
        public ModInt add(ModInt mi) {
            return new ModInt(ma.add(value, mi.value));
        }
        public ModInt add(ModInt mi1, ModInt mi2) {
            return new ModInt(ma.add(value, mi1.value)).addAsg(mi2);
        }
        public ModInt add(ModInt mi1, ModInt mi2, ModInt mi3) {
            return new ModInt(ma.add(value, mi1.value)).addAsg(mi2).addAsg(mi3);
        }
        public ModInt add(ModInt mi1, ModInt mi2, ModInt mi3, ModInt mi4) {
            return new ModInt(ma.add(value, mi1.value)).addAsg(mi2).addAsg(mi3).addAsg(mi4);
        }
        public ModInt add(ModInt mi1, ModInt... mis) {
            ModInt mi = add(mi1);
            for (ModInt m : mis) mi.addAsg(m);
            return mi;
        }
        public ModInt add(long mi) {
            return new ModInt(ma.add(value, ma.remainder(mi)));
        }
        public ModInt sub(ModInt mi) {
            return new ModInt(ma.sub(value, mi.value));
        }
        public ModInt sub(long mi) {
            return new ModInt(ma.sub(value, ma.remainder(mi)));
        }
        public ModInt mul(ModInt mi) {
            return new ModInt(ma.mul(value, mi.value));
        }
        public ModInt mul(ModInt mi1, ModInt mi2) {
            return new ModInt(ma.mul(value, mi1.value)).mulAsg(mi2);
        }
        public ModInt mul(ModInt mi1, ModInt mi2, ModInt mi3) {
            return new ModInt(ma.mul(value, mi1.value)).mulAsg(mi2).mulAsg(mi3);
        }
        public ModInt mul(ModInt mi1, ModInt mi2, ModInt mi3, ModInt mi4) {
            return new ModInt(ma.mul(value, mi1.value)).mulAsg(mi2).mulAsg(mi3).mulAsg(mi4);
        }
        public ModInt mul(ModInt mi1, ModInt... mis) {
            ModInt mi = mul(mi1);
            for (ModInt m : mis) mi.mulAsg(m);
            return mi;
        }
        public ModInt mul(long mi) {
            return new ModInt(ma.mul(value, ma.remainder(mi)));
        }
        public ModInt div(ModInt mi) {
            return new ModInt(ma.div(value, mi.value));
        }
        public ModInt div(long mi) {
            return new ModInt(ma.div(value, ma.remainder(mi)));
        }
        public ModInt inv() {
            return new ModInt(ma.inv(value));
        }
        public ModInt pow(long b) {
            return new ModInt(ma.pow(value, b));
        }
        public ModInt addAsg(ModInt mi) {
            this.value = ma.add(value, mi.value);
            return this;
        }
        public ModInt addAsg(ModInt mi1, ModInt mi2) {
            return addAsg(mi1).addAsg(mi2);
        }
        public ModInt addAsg(ModInt mi1, ModInt mi2, ModInt mi3) {
            return addAsg(mi1).addAsg(mi2).addAsg(mi3);
        }
        public ModInt addAsg(ModInt mi1, ModInt mi2, ModInt mi3, ModInt mi4) {
            return addAsg(mi1).addAsg(mi2).addAsg(mi3).addAsg(mi4);
        }
        public ModInt addAsg(ModInt... mis) {
            for (ModInt m : mis) addAsg(m);
            return this;
        }
        public ModInt addAsg(long mi) {
            this.value = ma.add(value, ma.remainder(mi));
            return this;
        }
        public ModInt subAsg(ModInt mi) {
            this.value = ma.sub(value, mi.value);
            return this;
        }
        public ModInt subAsg(long mi) {
            this.value = ma.sub(value, ma.remainder(mi));
            return this;
        }
        public ModInt mulAsg(ModInt mi) {
            this.value = ma.mul(value, mi.value);
            return this;
        }
        public ModInt mulAsg(ModInt mi1, ModInt mi2) {
            return mulAsg(mi1).mulAsg(mi2);
        }
        public ModInt mulAsg(ModInt mi1, ModInt mi2, ModInt mi3) {
            return mulAsg(mi1).mulAsg(mi2).mulAsg(mi3);
        }
        public ModInt mulAsg(ModInt mi1, ModInt mi2, ModInt mi3, ModInt mi4) {
            return mulAsg(mi1).mulAsg(mi2).mulAsg(mi3).mulAsg(mi4);
        }
        public ModInt mulAsg(ModInt... mis) {
            for (ModInt m : mis) mulAsg(m);
            return this;
        }
        public ModInt mulAsg(long mi) {
            this.value = ma.mul(value, ma.remainder(mi));
            return this;
        }
        public ModInt divAsg(ModInt mi) {
            this.value = ma.div(value, mi.value);
            return this;
        }
        public ModInt divAsg(long mi) {
            this.value = ma.div(value, ma.remainder(mi));
            return this;
        }
        @Override
        public String toString() {
            return String.valueOf(value());
        }
        @Override
        public boolean equals(Object o) {
            if (o instanceof ModInt) {
                ModInt mi = (ModInt) o;
                return mod() == mi.mod() && value() == mi.value();
            }
            return false;
        }
        @Override
        public int hashCode() {
            return (1 * 37 + mod()) * 37 + value();
        }
    }

    private interface ModArithmetic {
        public int mod();
        public int remainder(long value);
        public int add(int a, int b);
        public int sub(int a, int b);
        public int mul(int a, int b);
        public default int div(int a, int b) {
            return mul(a, inv(b));
        }
        public int inv(int a);
        public int pow(int a, long b);
    
        public static ModArithmetic of(int mod) {
            if (mod <= 0) {
                throw new IllegalArgumentException();
            } else if (mod == 1) {
                return new ModArithmetic1();
            } else if (mod == 2) {
                return new ModArithmetic2();
            } else if (mod == 998244353) {
                return new ModArithmetic998244353();
            } else if (mod == 1000000007) {
                return new ModArithmetic1000000007();
            } else if ((mod & 1) == 1) {
                return new ModArithmeticMontgomery(mod);
            } else {
                return new ModArithmeticBarrett(mod);
            }
        }
    
        static final class ModArithmetic1 implements ModArithmetic {
            public int mod() {return 1;}
            public int remainder(long value) {return 0;}
            public int add(int a, int b) {return 0;}
            public int sub(int a, int b) {return 0;}
            public int mul(int a, int b) {return 0;}
            public int inv(int a) {throw new ArithmeticException("divide by zero");}
            public int pow(int a, long b) {return 0;}
        }
        static final class ModArithmetic2 implements ModArithmetic {
            public int mod() {return 2;}
            public int remainder(long value) {return (int) (value & 1);}
            public int add(int a, int b) {return a ^ b;}
            public int sub(int a, int b) {return a ^ b;}
            public int mul(int a, int b) {return a & b;}
            public int inv(int a) {
                if (a == 0) throw new ArithmeticException("divide by zero");
                return a;
            }
            public int pow(int a, long b) {
                if (b == 0) return 1;
                return a;
            }
        }
        static final class ModArithmetic998244353 implements ModArithmetic {
            private final int mod = 998244353;
            public int mod() {
                return mod;
            }
            public int remainder(long value) {
                return (int) ((value %= mod) < 0 ? value + mod : value);
            }
            public int add(int a, int b) {
                int res = a + b;
                return res >= mod ? res - mod : res;
            }
            public int sub(int a, int b) {
                int res = a - b;
                return res < 0 ? res + mod : res;
            }
            public int mul(int a, int b) {
                return (int) (((long) a * b) % mod);
            }
            public int inv(int a) {
                int b = mod;
                long u = 1, v = 0;
                while (b >= 1) {
                    long t = a / b;
                    a -= t * b;
                    int tmp1 = a; a = b; b = tmp1;
                    u -= t * v;
                    long tmp2 = u; u = v; v = tmp2;
                }
                u %= mod;
                if (a != 1) {
                    throw new ArithmeticException("divide by zero");
                }
                return (int) (u < 0 ? u + mod : u);
            }
            public int pow(int a, long b) {
                if (b < 0) throw new ArithmeticException("negative power");
                long res = 1;
                long pow2 = a;
                long idx = 1;
                while (b > 0) {
                    long lsb = b & -b;
                    for (; lsb != idx; idx <<= 1) {
                        pow2 = (pow2 * pow2) % mod;
                    }
                    res = (res * pow2) % mod;
                    b ^= lsb;
                }
                return (int) res;
            }
        }
        static final class ModArithmetic1000000007 implements ModArithmetic {
            private final int mod = 1000000007;
            public int mod() {
                return mod;
            }
            public int remainder(long value) {
                return (int) ((value %= mod) < 0 ? value + mod : value);
            }
            public int add(int a, int b) {
                int res = a + b;
                return res >= mod ? res - mod : res;
            }
            public int sub(int a, int b) {
                int res = a - b;
                return res < 0 ? res + mod : res;
            }
            public int mul(int a, int b) {
                return (int) (((long) a * b) % mod);
            }
            public int div(int a, int b) {
                return mul(a, inv(b));
            }
            public int inv(int a) {
                int b = mod;
                long u = 1, v = 0;
                while (b >= 1) {
                    long t = a / b;
                    a -= t * b;
                    int tmp1 = a; a = b; b = tmp1;
                    u -= t * v;
                    long tmp2 = u; u = v; v = tmp2;
                }
                u %= mod;
                if (a != 1) {
                    throw new ArithmeticException("divide by zero");
                }
                return (int) (u < 0 ? u + mod : u);
            }
            public int pow(int a, long b) {
                if (b < 0) throw new ArithmeticException("negative power");
                long res = 1;
                long pow2 = a;
                long idx = 1;
                while (b > 0) {
                    long lsb = b & -b;
                    for (; lsb != idx; idx <<= 1) {
                        pow2 = (pow2 * pow2) % mod;
                    }
                    res = (res * pow2) % mod;
                    b ^= lsb;
                }
                return (int) res;
            }
        }
        static final class ModArithmeticMontgomery extends ModArithmeticDynamic {
            private final long negInv;
            private final long r2, r3;
    
            private ModArithmeticMontgomery(int mod) {
                super(mod);
                long inv = 0;
                long s = 1, t = 0;
                for (int i = 0; i < 32; i++) {
                    if ((t & 1) == 0) {
                        t += mod;
                        inv += s;
                    }
                    t >>= 1;
                    s <<= 1;
                }
                long r = (1l << 32) % mod;
                this.negInv = inv;
                this.r2 = (r * r) % mod;
                this.r3 = (r2 * r) % mod;
            }
            private int generate(long x) {
                return reduce(x * r2);
            }
            private int reduce(long x) {
                x = (x + ((x * negInv) & 0xffff_ffffl) * mod) >>> 32;
                return (int) (x < mod ? x : x - mod);
            }
            @Override
            public int remainder(long value) {
                return generate((value %= mod) < 0 ? value + mod : value);
            }
            @Override
            public int mul(int a, int b) {
                return reduce((long) a * b);
            }
            @Override
            public int inv(int a) {
                a = super.inv(a);
                return reduce(a * r3);
            }
            @Override
            public int pow(int a, long b) {
                return generate(super.pow(a, b));
            }
        }
        static final class ModArithmeticBarrett extends ModArithmeticDynamic {
            private static final long mask = 0xffff_ffffl;
            private final long mh;
            private final long ml;
            private ModArithmeticBarrett(int mod) {
                super(mod);
                /**
                 * m = floor(2^64/mod)
                 * 2^64 = p*mod + q, 2^32 = a*mod + b
                 * => (a*mod + b)^2 = p*mod + q
                 * => p = mod*a^2 + 2ab + floor(b^2/mod)
                 */
                long a = (1l << 32) / mod;
                long b = (1l << 32) % mod;
                long m = a * a * mod + 2 * a * b + (b * b) / mod;
                mh = m >>> 32;
                ml = m & mask;
            }
            private int reduce(long x) {
                long z = (x & mask) * ml;
                z = (x & mask) * mh + (x >>> 32) * ml + (z >>> 32);
                z = (x >>> 32) * mh + (z >>> 32);
                x -= z * mod;
                return (int) (x < mod ? x : x - mod);
            }
            @Override
            public int remainder(long value) {
                return (int) ((value %= mod) < 0 ? value + mod : value);
            }
            @Override
            public int mul(int a, int b) {
                return reduce((long) a * b);
            }
        }
        static class ModArithmeticDynamic implements ModArithmetic {
            final int mod;
            public ModArithmeticDynamic(int mod) {
                this.mod = mod;
            }
            public int mod() {
                return mod;
            }
            public int remainder(long value) {
                return (int) ((value %= mod) < 0 ? value + mod : value);
            }
            public int add(int a, int b) {
                int sum = a + b;
                return sum >= mod ? sum - mod : sum;
            }
            public int sub(int a, int b) {
                int sum = a - b;
                return sum < 0 ? sum + mod : sum;
            }
            public int mul(int a, int b) {
                return (int) (((long) a * b) % mod);
            }
            public int inv(int a) {
                int b = mod;
                long u = 1, v = 0;
                while (b >= 1) {
                    long t = a / b;
                    a -= t * b;
                    int tmp1 = a; a = b; b = tmp1;
                    u -= t * v;
                    long tmp2 = u; u = v; v = tmp2;
                }
                u %= mod;
                if (a != 1) {
                    throw new ArithmeticException("divide by zero");
                }
                return (int) (u < 0 ? u + mod : u);
            }
            public int pow(int a, long b) {
                if (b < 0) throw new ArithmeticException("negative power");
                int res = 1;
                int pow2 = a;
                long idx = 1;
                while (b > 0) {
                    long lsb = b & -b;
                    for (; lsb != idx; idx <<= 1) {
                        pow2 = mul(pow2, pow2);
                    }
                    res = mul(res, pow2);
                    b ^= lsb;
                }
                return res;
            }
        }
    }
}

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int S = sc.nextInt();

        ModIntFactory mf = new ModIntFactory(1000000007);
        ModIntFactory.ModInt[] fact = new ModIntFactory.ModInt[10000];
        fact[0] = mf.create(1);
        for(int i=1; i<10000; i++) fact[i] = fact[i-1].mul(i);
        ModIntFactory.ModInt[] finv = new ModIntFactory.ModInt[10000];
        finv[9999] = fact[9999].inv();
        for(int i=9998; i>=0; i--) finv[i] = finv[i+1].mul(i+1);
        
        var ans = mf.create(0);
        for(int size=1; size*3<=S; size++){
            int s = S - 3*size;
            //sを非負整数size個に分ける -> |*(size-1), o*sの並べ替え
            // (s+size-1) C s 
            ans.addAsg(fact[s+size-1].mul(finv[s], finv[size-1]));
        }
        System.out.println(ans);
    }
}