Let's denote d(n) as the number of divisors of a positive integer n. You are given three integers a, b and c. Your task is to calculate the following sum:

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Find the sum modulo 1073741824 (230).

Input

The first line contains three space-separated integers a, b and c (1 ≤ a, b, c ≤ 100).

Output

Print a single integer — the required sum modulo 1073741824 (230).

Examples

Input

2 2 2


Output

20


Input

5 6 7


Output

1520

Note

For the first example.

  * d(1·1·1) = d(1) = 1; 
  * d(1·1·2) = d(2) = 2; 
  * d(1·2·1) = d(2) = 2; 
  * d(1·2·2) = d(4) = 3; 
  * d(2·1·1) = d(2) = 2; 
  * d(2·1·2) = d(4) = 3; 
  * d(2·2·1) = d(4) = 3; 
  * d(2·2·2) = d(8) = 4. 



So the result is 1 + 2 + 2 + 3 + 2 + 3 + 3 + 4 = 20.
import java.io.*;
import java.util.*;

public class Main { 
    public static void main(String[] args) throws IOException { 
        InputStream input = System.in;
        OutputStream output = System.out;
        InputReader in = new InputReader(input);
        PrintWriter out = new PrintWriter(output);
        Solution s = new Solution();
        s.solve(1, in, out);
        out.close();
    }

    static class Solution { 
        
        double EPS = 0.0000001;
        int[] divisors;
        int M = 1073741824;
        public void solve(int cs, InputReader in, PrintWriter out) {
            int a = in.nextInt(), b = in.nextInt(), c = in.nextInt();
            int max = Math.max(a, Math.max(b, c));
            divisors = new int[a*b*c+2];
            sieve(a*b*c+1);
            int count = 0;
            for (int i = 1; i <= a; ++i) {
                for (int j = 1; j <= b; ++j) {
                    for (int k = 1; k <= c; ++k)
                        count += divisors[i*j*k]%M;
                }
            }
            out.println(count);


        }

        void sieve(int n) {
            divisors[0] = divisors[1] = 1;
            for (int i = 2; i <= n; ++i) {
                if (divisors[i] == 0) {
                    for (int j = i; j <= n; j+=i) {
                        int e = 0;
                        int q = j;
                        while (q%i==0) {
                            ++e;
                            q/=i;
                        }
                        if (divisors[j] != 0)
                                divisors[j]*=(e+1);
                        else
                            divisors[j] = e+1;
                    }
                }
            }
        }
    }

    static class InputReader { 
        BufferedReader br;
        StringTokenizer st;
        
        public InputReader(InputStream i) {
            br = new BufferedReader(new InputStreamReader(i), 32768);
            st = null;
        }

        public InputReader(FileReader s) {
            br = new BufferedReader(s);
            st = null;
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try { 
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return st.nextToken();
        }

        public int nextInt() { 
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public double nextDouble() {
            return Double.parseDouble(next());
        }

        public String nextLine() { 
            try { 
                return br.readLine();
            } catch (IOException e) { 
                throw new RuntimeException(e);
            }
        }
    }
    static class Reader {
        final private int BUFFER_SIZE = 1 << 16;
        private DataInputStream din;
        private byte[] buffer;
        private int bufferPointer, bytesRead;
        public Reader(){
            din=new DataInputStream(System.in);
            buffer=new byte[BUFFER_SIZE];
            bufferPointer=bytesRead=0;
        }

        public Reader(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();
        }
    }
}


