#include <bits/stdc++.h>
using namespace std;
int main(void){
    int a,b;
    string s;
    cin>>a>>b>>s;
    a-=9;
    int diffa=0,diffb=0,fa=1,fb=1;
    int flag=0;
    if(s[3]=='-'){
        fa=-1;
        fb=-1;
    }
    for(int i=4;i<s.size();i++){
        if(s[i]=='.'){
            flag=1;
        }else if(!flag){
            diffa*=10;
            diffa+=s[i]-'0';
        }else{
            diffb=(s[i]-'0')*6;
        }
    }
    a+=diffa*fa;
    b+=diffb*fb;
    while(b<0){
        b+=60;
        a--;
    }
    while(b>=60){
        b-=60;
        a++;
    }
    while(a<0){
        a+=24;
    }
    while(a>=24){
        a-=24;
    }
    cout<<(a<10?"0":"")<<a<<":"<<(b<10?"0":"")<<b<<endl;
    return 0;
}