题解

#include<iostream>
#include<cmath>
using namespace std;
int main(){
    int x,y,z;
    cin>>x>>y>>z;
    cout<<ceil((ceil((x+y+z)/3.0)+ceil((3*x+5*y+7*z)/4.0)+ceil((11*x+13*y+17*z)/5.0))/7.0);
    return 0;
}