DFS Acdrean 1431

C-sum vs ProductTime limit:1000MS Memory Limit:64000KB 64bit IO Format:%lld &%llu< /c7> SubmitStatusPracticeAcdream 1431Appoint Description:System Crawler (2015-04-16)

Description

Peter has just learned mathematics. He learned how to add, and what to multiply. The fact that 2 + 2 = 2x2 have amazed him greatly. Now he wants find more such examples. Peters calls a collection of numbers beautiful if the product of the numbers in it was equal to their sum.

For example, the collections {2, 2}, {5}, {1, 2, 3} were beautiful, but {2, 3} was not.

Given N, Peter wants to find the number of beautiful collections with n numbers. Help him!

Input

The first line of the input file contains n (2≤n≤500)

Output

Output one number-the number of the beautiful collections with n numbers.

Sample Input

25

Sample Output

13

Hint

The collections in the last example is: {1, 1, 1, 2, 5}, {1, 1, 1, 3, 3} and {1, 1, 2, 2, 2}.

#include <iostream> #include <cstdio> #include <cstring> #include <string> #include <cmath > #include <cstdlib> #include <algorithm> #include <queue> #include <vector> #include < stack>using namespace Std;int n,ans;void dfs (int x,int k,int product,int sum) {for    (int i=x;i>=2;i--)    {        if (product*i>sum+i+n-k) continue;        else if (product*i==sum+i+n-k) ans++;        else Dfs (i,k+1,product*i,sum+i);}    } int main () {    scanf ("%d", &n);    DFS (n,1,1,0);    printf ("%d\n", ans);    return 0;}

　　

DFS Acdrean 1431