#include "bits/stdc++.h"
using namespace std;
#define fastcin {\
    cin.tie(0);\
    ios::sync_with_stdio(false);\
}
#define rep(i, a, b) for(int i = a; i < b; i++)
#define rrep(i, a, b) for(int i = a; i >= b; i--)
#define fore(i, a) for(auto &i:a)
#define print(x) cout << x << "\n"
#define SORT(a, n) sort(a, a+n);
#define REVERSE(a,n) reverse(a,a+n);
#define VSORT(v) sort(v.begin(), v.end());
#define VREVERSE(v) reverse(v.begin(), v.end());
#define MOD 1000000007
#define yes "YES"
#define no "NO"
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;

int main() {
    fastcin;
    string t;
    cin >> t;
    int h = (t[0]-'0')*10 + (t[1]-'0');
    int m = (t[3]-'0')*10 + (t[4]-'0');
    m = m+5;
    if(m > 59) {
        m %= 60;
        h++;
        if(h > 23) h = 0;
    }
    printf("%02d:%02d\n", h, m);
    return 0;
}