import java.io.*;
import java.util.*;
import java.util.stream.*;

// 処理
class Process {
    private String T;

    Process(String T) {
        this.T = T;
    }

    private int timeToNum() {
        int[] times = Stream.of(T.split(":")).mapToInt(Integer::parseInt).toArray();

        return (times[0] * 60 + times[1]);
    }

    private String numToTime(int n) {
        var result = new StringBuilder("");
        int hour   = n / 60;
        int minute = n % 60;
        
        result.append((hour < 10) ? "0" : "");
        result.append(hour);
        result.append(":");
        result.append((minute < 10) ? "0" : "");
        result.append(minute);

        return result.toString();
    }

    String getResult() {
        return numToTime((timeToNum() + 5) % 1440);
    }
}

public class Main {
    public static void main(String[] args) throws IOException {
        var bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        var printWriter    = new PrintWriter(new BufferedWriter(new OutputStreamWriter(System.out)));

        // 入力
        String T = bufferedReader.readLine().trim();

        // 出力
        printWriter.println((new Process(T)).getResult());

        bufferedReader.close();
        printWriter.close();
    }
}