Codeforce - vasya and chocolate

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
    ll t,s,a,b,c,r,res;
    scanf("%I64d",&t);
    while(t--)
    {
        scanf("%I64d %I64d %I64d %I64d",&s,&a,&b,&c);
        res=s/c;
        r=(res/a)*b;
        res+=r;
        printf("%I64d\n",res);
    }
    return 0;
}