RT，我的代码：

#include<iostream>
#include<sstream>
using namespace std;
int t,s,v,h=7,m=59;
string sh,sm;
int main(){
    cin>>s>>v;
    t=s/v+10;
    for (int i=0;i<t;i++){
        m-=1;
        if(m<0){
                m=59;
                h-=1;
            if(h<0){
                h=23;
            }
        }
    }
    if(h<10){
        sh='0'+to_string(h);
    }else{
        sh=to_string(h);
    }
    if(m<10){
        sm='0'+to_string(m);
    }else{
        sm=to_string(m);
    }
    cout<<sh<<":"<<sm;
}

错误：

Wrong Answer.wrong answer On line 1 column 5, read 2, expected 3