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.*;
import java.io.*;
import java.math.*;
public class Main{
	static long mod = (long)(1e9+7);
	public static PrintWriter out = new PrintWriter (new BufferedOutputStream(System.out));
	public static void main(String[] args)throws IOException {
		Scanner sc =new Scanner(System.in);
		//FastReader sc = new FastReader();
		int n = sc.nextInt();
		long dp[]  = new long[n+1];
		dp[0]=1;
		for(int i=3;i<=n;i++){
			for(int j=3;j<=n;j++){
				if(i-j>=0)
					dp[i] = (dp[i-j]%mod + dp[i]%mod)%mod;
			}
		}
		System.out.println(dp[n]);
	}
	
	public static void add(HashMap<Integer,Integer> hm, int val){
		if(!hm.containsKey(val))
			hm.put(val,1);
		else hm.put(val, hm.get(val)+1);
	}
	
	public static void remove(HashMap<Integer,Integer> hm, int val){
		hm.put(val, hm.get(val)-1);
		if(hm.get(val)==0){
			hm.remove(val);
		}
	}
			
			
	public static long power(long a, long b){
		
		long temp = 0;
		if(b==0)
			return 1;
		
		temp = power(a, b/2);
		if(b%2==0)
			return (temp%mod*temp%mod)%mod;
		return (a%mod*(temp%mod*temp%mod)%mod)%mod;
	}
	
	public static ArrayList<Integer> primefactor(int n){
		int sqrt = (int)Math.sqrt(n);
		ArrayList<Integer> al = new ArrayList<>();
		while(n%2==0){
			al.add(2);
			n/=2;
		}
		for(int i=3;i<=sqrt;i+=2){
			while(n%i==0){
				al.add(i);
				n/=i;
			}
		}
		if(n>2)
			al.add(n);
		return al;
	}
	
	public static long sum(long val){
		long fg =0 ;
		while(val!=0){
			fg+=val%10;
			val/=10;
		}
		return fg;
	}
	
	
	
	public static ArrayList<Long> factor(long n){
		long sqrt = (long)Math.sqrt(n);
		ArrayList<Long> al = new ArrayList<>();
		for(long i=1;i<=sqrt;i++){
			if(n%i!=0)
				continue;
			long first = i;
			long second = n/i;
			al.add(i);
			if(first==second){
				continue;
			}
			al.add(n/i);
		}
		return al;
	}
	
	
	
	public static ArrayList<Integer> comp(){
		ArrayList<Integer> al = new ArrayList<>();
			int n = (int)2e5;
			boolean arr[] = new boolean[n+1];
			int sqrt = (int)Math.sqrt(n);
			for(int i=2;i<=sqrt;i++){
				if(arr[i]==false){
					for(int j=i*i;j<=n;j+=i){
						arr[j]=true;
					}
				}
			}
			for(int i=2;i<=n;i++){
				if(arr[i]==false)
					al.add(i);
			}
			
		return al;
	}
	
	public static class pair{
		long a;
		int b;
		pair(long x, int y){
			a=x;
			b=y;
		}
	}
	
	public static class comp implements Comparator<pair>{
		public int compare(pair o1, pair o2){
			return Long.valueOf(o1.a).compareTo(Long.valueOf(o2.a));
		}
	}
	
	
	
	static class Node{
		int node;
		int d;
		ArrayList<Integer> al = new ArrayList<>();	
	}
	

	static int gcd(int a, int b) 
    { 
      if (b == 0) 
        return a; 
      return gcd(b, a % b);  
    }
	
		
	static class FastReader 
	{ 
		final private int BUFFER_SIZE = 1 << 16; 
		private DataInputStream din; 
		private byte[] buffer; 
		private int bufferPointer, bytesRead; 
  
		public FastReader() 
		{ 
			din = new DataInputStream(System.in); 
			buffer = new byte[BUFFER_SIZE]; 
			bufferPointer = bytesRead = 0; 
		} 
  
		public FastReader(String file_name) throws IOException 
		{ 
			din = new DataInputStream(new FileInputStream(file_name)); 
			buffer = new byte[BUFFER_SIZE]; 
			bufferPointer = bytesRead = 0; 
		} 
  
		public String readLine() throws IOException 
		{ 
			byte[] buf = new byte[64]; // line length 
			int cnt = 0, c; 
			while ((c = read()) != -1) 
			{ 
				if (c == '\n') 
					break; 
				buf[cnt++] = (byte) c; 
			} 
			return new String(buf, 0, cnt); 
		} 
  
		public int nextInt() throws IOException 
		{ 
			int ret = 0; 
			byte c = read(); 
			while (c <= ' ') 
				c = read(); 
			boolean neg = (c == '-'); 
			if (neg) 
				c = read(); 
			do
			{ 
				ret = ret * 10 + c - '0'; 
			}  while ((c = read()) >= '0' && c <= '9'); 
  
			if (neg) 
				return -ret; 
			return ret; 
		} 
  
		public long nextLong() throws IOException 
		{ 
			long ret = 0; 
			byte c = read(); 
			while (c <= ' ') 
				c = read(); 
			boolean neg = (c == '-'); 
			if (neg) 
				c = read(); 
			do { 
				ret = ret * 10 + c - '0'; 
			} 
			while ((c = read()) >= '0' && c <= '9'); 
			if (neg) 
				return -ret; 
			return ret; 
		} 
  
		public double nextDouble() throws IOException 
		{ 
			double ret = 0, div = 1; 
			byte c = read(); 
			while (c <= ' ') 
				c = read(); 
			boolean neg = (c == '-'); 
			if (neg) 
				c = read(); 
  
			do { 
				ret = ret * 10 + c - '0'; 
			} 
			while ((c = read()) >= '0' && c <= '9'); 
  
			if (c == '.') 
			{ 
				while ((c = read()) >= '0' && c <= '9') 
				{ 
					ret += (c - '0') / (div *= 10); 
				} 
			} 
  
			if (neg) 
				return -ret; 
			return ret; 
		} 
		
		
  
		private void fillBuffer() throws IOException 
		{ 
			bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
			if (bytesRead == -1) 
				buffer[0] = -1; 
		} 
  
		private byte read() throws IOException 
		{ 
			if (bufferPointer == bytesRead) 
				fillBuffer(); 
			return buffer[bufferPointer++]; 
		} 
  
		public void close() throws IOException 
		{ 
			if (din == null) 
				return; 
			din.close(); 
		} 
	} 
}