n = int(input("Enter Number: "))
totient = [i for i in range(n+1)]
for i in range(2, n+1):
    if totient[i] == i:
        for j in range(2*i, n+1, i):
            totient[j] *= i-1
            totient[j] /= i
        totient[i] = i-1
print("totient:", totient[n])

# Coded by Saahil