function extraLongFactorials(n: number): void {
    let answer: bigint = BigInt(1);

    while (n > 0) {
        answer *= BigInt(n);
        n--;
    }
    
    console.log(answer.toString());
}

def extraLongFactorials(n):
    # Write your code here
    result = 1
    
    for i in range(1, n+1):
        result *= i
        i -= 1   

    print(result)

def extraLongFactorials(n):
  if n == 1:
    return 1
  return n * extraLongFactorials(n - 1)



if __name__ == '__main__':
    n = int(input().strip())

    print(extraLongFactorials(n))

function extraLongFactorials(n) {
    // Write your code here
    let fact = BigInt(1);
    for(let i = 1; i <= n; i++){
        fact = fact * BigInt(i);
    }
    console.log(fact.toString());
}

def factorial(num):
    if num == 1:
        return 1

    return num * factorial(num - 1)

num = int(input())
print(factorial(num))