Решение задачи Время прибытия с Acmp

#include <iostream>
 
using namespace std;
 
int main()
{
    string str;
    cin >> str;
    int n,m,k = 0;
    cin >> n >> m;
    int a = (str[0] - 48) * 10+ str[1] - 48;
    int b = (str[3] - 48) * 10+ str[4] - 48;
    int minu = a * 60 + b + n * 60 + m;
    int soat = minu / 60;
    int minuta = minu - (soat * 60);
    while(minuta > 60){
        minuta-=60;
        k++;
    }
    soat+=k;
    while(soat >= 24){
        soat-=24;
    }
 
    if(soat < 10)
        cout << "0" << soat;
    else
        cout << soat;
    cout << ":";
    if(minuta < 10)
        cout << "0" << minuta;
    else
        cout << minuta;
 
    return 0;
}