def pisano_period(n):
    a, b = 0, 1
    for i in range(n * n):
        a, b = b, (a + b) % n
        if a == 0 and b == 1:
            return i + 1

def find_a_N(N):
    if N >= 3:
        return pisano_period(N) // 2
    else:
        return pisano_period(N)

if __name__ == "__main__":
    import sys
    N = int(input().strip())
    print(find_a_N(N))