import sys

def solve():
    n = int(input())

    if n % 4 == 0:
        nimsum = n
    elif n % 4 == 1:
        nimsum = 1
    elif n % 4 == 2:
        nimsum = n + 1
    else:
        nimsum = 0

    print('O' if nimsum != 0 else 'X')

if __name__ == '__main__':
    solve()