#include<bits/stdc++.h>
using namespace std;
typedef long long ll;

signed main(){
    ios::sync_with_stdio(false);
	cin.tie(0);
 
    int a,b;
    string s;
    cin>>a>>b>>s;
    int n=s.size();
    int t=48;
    if(s[4]=='+'){
        if(n==5){
            t+= (int)s[n-1] - '0';
            a+=t-9;
            a+=24;
            a%=24;
        }
        else if(n==6){
            t+= (int)s[4] - '0';
            t*=10;
            t += (int)s[5] - '0';
            a+=t-9;
            a+=24;
            a%=24;
        }
        else if(n==7){
            t=(int)s[4]-'0';
            a+=t-9+24;
            a%=24;
            t+= (int) s[n-1]-'0';
            t*=6;
            b+=t;
            if(b>=60) a++;
            a%=24;
            b%=60;
        }
        else {
            t+= (int)s[4] - '0';
            t*=10;
            t += (int)s[5] - '0';
            a+=t-9+24;
            a%=24;
            t+= (int) s[n-1]-'0';
            t*=6;
            b+=t;
            if(b>=60) a++;
            a%=24;
            b%=60;
        }
    }
    else {
        if(n==5){
            t+= (int)s[n-1] - '0';
            a+=-t-9;
            a+=24;
            a%=24;
        }
        else if(n==6){
            t+= (int)s[4] - '0';
            t*=10;
            t += (int)s[5] - '0';
            a+=-t-9;
            a+=24;
            a%=24;
        }
        else if(n==7){
            t=(int)s[4]-'0';
            a+=-t-9+24;
            a%=24;
            t= (int) s[n-1]-'0';
            t*=6;
            b-=t;
            if(b<0) a+=23,b+=60;
            a%=24;
            b%=60;
        }
        else {
            t+= (int)s[4] - '0';
            t*=10;
            t += (int)s[5] - '0';
            a+=-t-9+24;
            a%=24;
            t= (int) s[n-1]-'0';
            t*=6;
            b-=t;
           if(b<0) a+=23,b+=60;
            a%=24;
            b%=60;
        }
    }

    if(a<10){
        cout<<0<<a<<":";
    }
    else cout<<a<<":";
    if(b<10){
        cout<<0<<b<<endl;
    }
    else cout<<b<<endl;
    
}