#include <bits/stdc++.h>

int main() {
std::stringstream ss;
std::string s;
int k = 0;
int a[2] {};
while(ss>>s) {
if(s == ":") {
k++;
} else {
std::cin >> a[k];
}
}
int b = a[0] * 60 + a[1] + 5;
printf("%02d:02d\n", b/60%24, a[1]%60);
}