70分(后三个错)c++

#include<bits/stdc++.h>
using namespace std;
int s,u,g,d,v,f;
int main(){
    cin>>s>>u;
    if(s%u!=0){
        f=s/u+1;
    }else{
        f=s/u;
    }
    d=480-10-f;
    if(d/60<10){
        g=d/60;
        v=d-g*60;
        if(v<10){
            cout<<"0"<<g<<":"<<"0"<<v;
        }else{
            cout<<"0"<<g<<":"<<v;
        }
    }else{
        g=d/60;
        v=d-g*60;
        if(v<10){
            cout<<g<<":"<<"0"<<v;
        }else{
            cout<<g<<":"<<v;
        }
    }
    return 0;
}