#include <iostream>
#include <string>
using namespace std;

int main()
{
    string time;
    cin >> time;
    if(time[0]=='1' && time[0] == '2')
    {
        if(time[time.length()-2] == 'A' )
        {
            time[0] = time[1] = '0';
        }

    }
    else
    {
        int x = ((time[0]-'0')*10) + (time[1]-'0');
        x += 12;
        if(x == 24)
            x = 0;
        time[0] = ((x/10)%10) + '0';
        time[1] = (x%10) + '0';
    }
    for(int i = 0; i < time.length()-2 ; i++)
            cout << time[i];
    return 0;
}