题解

#include <iostream>
#include<cmath>
using namespace std;

int main() {
double a,b,c;
cin >> a>>b>>c;

double q=(a+b+c)/3;

double w=(3*a+5*b+7*c)/4;

double e=(11*a+13*b+17*c)/5;
int s=ceil(q)+ceil(w)+ceil(e);
double k=s/7.0;
int n=ceil(k);
cout<<n;


return 0;

}