萌新求助，一直测试不成功，请各位大佬指点

#include<iostream>
using namespace std;
int main(){
int m=1e9+7;
int n;
cin>>n;
int i,r;
for(i=1;i<=3;i++){
int a,b;
cin>>a>>b;
r=(n/a+1)*b;
if(r<m)
m=r;
}
cout<<m<<endl;
return 0;
}