Лена

#include <iostream>
#include <string>

using namespace std;

int daysInMonth[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
string dayName[] = {"Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday"};

bool isLeap(int year) {
    return !(year % 4) && (year % 100) || !(year % 400);
}

int getDayNumber(int year, int month, int day) {
    int currentDay = 2;
    --month;
    for (int i = 1800; i < year; ++i) currentDay = (currentDay + 365 + isLeap(i)) % 7;
    for (int i = 0; i < month; ++i) currentDay = (currentDay + daysInMonth[i]) % 7;
    if (isLeap(year) && month > 1) currentDay = (++currentDay) % 7;
    currentDay = (currentDay + day - 1) % 7;
    return currentDay;
}

int main() {
    int year, month, day;
    cin >> day >> month >> year;
    cout << dayName[getDayNumber(year, month, day)] << endl;
    return 0;
}