v1_4_1

#include <iostream>

using namespace std;

struct date
{
    int day, month, year;
};

bool vis(int year)
{
    if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
        return true;
    else
        return false;
}

int whatday(int month, int year)
{
    if (month == 3)
        {
            if (vis(year) == true)
                return 29;
            else
                return 28;
        }
    else
        {
            if (month == 8 || (month < 8 && month % 2 == 0) || (month > 8 && month % 2 != 0))
                return 31;
            else
                return 30;
        }
}

int main()
{
    date a;
    cin >> a.day >> a.month >> a.year;
    if (a.day > 1)
        cout << a.day - 1 << "." << a.month << "." << a.year;
    else
    {
        if (a.month > 1)
            cout << whatday(a.month, a.year) << "." << a.month - 1 << "." << a.year;
        else
            cout << "31.12." << a.year - 1;
    }

    return 0;
}