// 9383635	sui1999	1211	Accepted	700K	0MS	G++	2620B	2011-10-02 15:39:55
#include <fstream>
#include <iostream>
#include <cstdio>

#define MAX_INT  0x7FFFFFFF
#define MAX_NUMS 101
#define MAX_N    5*60*60
using namespace std;

int signals[MAX_NUMS], signals_size, zeros, start, end, value;

int check(int start, int end, int index)
{
    if(index == signals_size)
    {
        if(end >= start)
            return start;

        return 0;
    }

    int mul       = start / (signals[index] << 1);

    int tmp_start = (signals[index] << 1) * mul;
    int tmp_end   = tmp_start + signals[index] - 6;

    while(tmp_start <= end)
    {
        if(tmp_start < start)
            tmp_start = start;

        if(tmp_end   > end)
            tmp_end   = end;

        int value;
        if(tmp_end   >= start)
            if((value = check(tmp_start, tmp_end, index+1)))
                return value;

        mul++;
        tmp_start = (signals[index] << 1) * mul;
        tmp_end   =  tmp_start + signals[index] - 6;
    }

    return 0;
}

int main()
{
    //std::ifstream cin("../data/case.in");

    zeros = 0;
    while(zeros != 3)
    {
        signals_size = 0, value = MAX_INT, start = 0;
        while(cin >> signals[signals_size], signals[signals_size])
        {
            if(value > signals[signals_size])
                value = signals[signals_size], start = signals_size;

            //std::cout << signals[signals_size] << " " << std::endl;;
            signals_size++, zeros = 0;
        }

        signals[start] = signals[0], signals[0] = value;

        if(signals_size)
        {
            start = signals[0] << 1, value = 0;
            while(start<= MAX_N)
            {
                if(start + signals[0] - 6 > MAX_N)
                    value = check(start, MAX_N, 1);
                else
                    value = check(start, start + signals[0] - 6, 1);

                if(value)
                {
                /*
                    std::cout.width(2);
                    std::cout.fill('0');
                    std::cout << value/3600 << ":" << (value%3600)/60 << ":" << value%60 << std::endl;
                */
                    printf("%02d:%02d:%02d\n", value/3600, (value%3600)/60, value%60);
                    break;
                }

                start += (signals[0] << 1);
            }

            if(!value)
                std::cout << "Signals fail to synchronise in 5 hours" << std::endl;

            signals_size = 0;
        }
        else if(!signals_size)
            zeros++;
    }

    //cin.close();

    return 0;
}