while True:
    year = int(input("Year: "))
    if year < 1583 or year > 9999:
        print("Out of range 1583 - 9999")
    else:
        break



while True:
    month = int(input("Month: "))
    if month < 1 or month > 12:
        print("Out of range 1 - 12")
    else:
        break

yearlist = []
for i in range(1600,9999,100):
    yearlist.append(i)

if year in yearlist and year % 400 == 0:
    a = 1
    while a == 1:
        day = int(input("Day: "))
        if month == 1 or month == 3 or month == 5 or month == 7 or month == 8 or month == 10 or month == 12 \
           and day > 31 or day < 1:
            print("Out of allowed range 1 - 31")
        elif month == 4 or month == 6 or month == 9 or month == 11 \
           and (day > 30 or day < 1):
            print("Out of allowed range 1 - 30")
        elif month == 2 and day > 29 or day < 1:
            print("Out of allowed range 1 - 29")
        else:
            a = 0
elif year not in yearlist and year % 4 == 0:
    a = 1
    while a == 1:
        day = int(input("Day: "))
        if month == 1 or month == 3 or month == 5 or month == 7 or month == 8 or month == 10 or month == 12 \
           and day > 31 or day < 1:
            print("Out of allowed range 1 - 31")
        elif month == 4 or month == 6 or month == 9 or month == 11 \
           and day > 30 or day < 1:
            print("Out of allowed range 1 - 30")
        elif month == 2 and day > 29 or day < 1:
            print("Out of allowed range 1 - 29")
        else:
            a = 0
else:
    a = 1
    while a == 1:
        day = int(input("Day: "))
        if month == 1 or month == 3 or month == 5 or month == 7 or month == 8 or month == 10 or month == 12 \
           and day > 31 or day < 1:
            print("Out of allowed range 1 - 31")
        elif month == 4 or month == 6 or month == 9 or month == 11 \
           and day > 30 or day < 1:
            print("Out of allowed range 1 - 30")
        elif month == 2 and day > 28 or day < 1:
            print("Out of allowed range 1 - 28")
        else:
            a = 0

if month == 1 or month == 2:
    month += 12
    year -= 1

zellerscongruence = ( day + 13*(month+1)//5 + year + year//4
                    - year//100 + year//400 ) % 7

if zellerscongruence == 0:
    print("It is a Saturday")
if zellerscongruence == 1:
    print("It is a Sunday")
if zellerscongruence == 2:
    print("It is a Monday")
if zellerscongruence == 3:
    print("It is a Tuesday")
if zellerscongruence == 4:
    print("It is a Wednesday")
if zellerscongruence == 5:
    print("It is a Thursday")
if zellerscongruence == 6:
    print("It is a Friday")