70分，求调

#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
double a,b,t1,t2=10,t3,c=1440,d,e,h;
int f,g,i;
int main()
{
    cin>>a>>b;
    t1=a/b;
    t3=t1+t2;
    d=c-t3;
    e=d/60;
    f=trunc(e)-24;
    h=d-trunc(e)*60; 
    i=trunc(h);
    if (8+f>0)
    {
        g=8+f;
    }
    else
    {
        g=32+f;
    }
    if(g<10)
    {

        cout<<"0"<<g<<":"<<i;
    }
    else
    {
        cout<<g<<":"<<i;
    }
    return 0;
}