#!/usr/bin/env python3
# %%
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines


# %%
N = int(read())

# %%
x = (N - 1) // 4 * 4
xor = 0
for i in range(x + 1, N + 1):
    xor ^= i

# %%
print('O' if xor else 'X')