题解

#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,num=0;
	cin>>n;
	for(int i=0;i<=n/5;i++){
		int b=(n-7*i)/4;
		int c=n-i-b;
		if(5*i+3*b+c/3==n&&b>=0&&c>=0&&c%3==0){
			num++;
		}
	}
	cout<<num;
	return 0;
}