import sys
from array import array

data = sys.stdin.read().split()
p = int(data[0])
if p == 2:
    print(1)
    sys.exit(0)
half = p // 2 + 1
inv = array('i', [0] * half)
inv[1] = 1
current_sum = 0
count = 0
for i in range(1, p):
    if i == 1:
        val = 1
    elif i < half:
        inv[i] = (p - (p // i) * inv[p % i]) % p
        val = inv[i]
    else:
        val = (p - (p // i) * inv[p % i]) % p
    current_sum = (current_sum + val) % p
    count += 1
    if count == 100:
        print(current_sum)
        current_sum = 0
        count = 0
if count > 0:
    print(current_sum)