n = int(input("enter a number:"))
n = n % 7
if n == 0:
    print("saturday")
elif n == 1:
    print("sunday")
elif n == 2:
    print("monday")
elif n == 3:
    print("tuesday")
elif n == 4:
    print("wednesday")
elif n == 5:
    print("thursday")
elif n == 6:
    print("friday")
else:
    print("invalid number")