暴力解题法

#include<bits/stdc++.h>
using namespace std;
int main(){
    int n,a1,a2,b1,b2,c1,c2,ta,tb,tc;
    cin>>n>>a1>>a2>>b1>>b2>>c1>>c2;
    if(n%a1==0)
        ta=n/a1*a2;
    else
        ta=(n/a1+1)*a2;
    if(n%b1==0)
        tb=n/b1*b2;
    else
        tb=(n/b1+1)*b2;
    if(n%c1==0)
        tc=n/c1*c2;
    else
        tc=(n/c1+1)*c2;
    int mix=ta;
    if(tb<=mix)
        mix=tb;
    if(tc<=mix)
        mix=tc;
    cout<<mix;
    return 0;
}