70分求助

#include <iostream>
#include <cstdio>
#include<stdio.h>
using namespace std;
 
int main ()
{
    int s,v,time1,t3,t2;
    cin>>s>>v;
    time1=s/v+10;
    t3=time1/60;
    t2=59-time1%60;
    t3=7-t3;
    if(s>v*24*60){
    	cout<<"0:00";
	}
    else{
    	printf("%02d:%02d",t3,t2);
    	
	}	
    
    return 0;
}