/**
 * Tittle:	10323 - Factorial! You Must be Kidding!!!
 * Author:	Cheng-Shih, Wong
 * Date:	2015/06/17
 */

// include files
#include <bits/stdc++.h>

using namespace std;

// definitions
#define FOR(i,a,b) for( int i=(a),_n=(b); i<=_n; ++i )
#define clr(x,v) memset( x, v, sizeof(x) )

typedef long long ll;

// declarations
int n;
ll fact[15];

// functions


// main function
int main( void )
{
	fact[0] = 1LL;
	FOR( i, 1, 13 )
		fact[i] = fact[i-1]*i;
	
	// input
	while( scanf( "%d", &n )==1 ) {
		if( n < 0 ) {
			if( ((-n)&1)==1 ) puts("Overflow!");
			else puts("Underflow!");
		} else {
			if( n<=7 ) puts("Underflow!");
			else if( n>=14 ) puts("Overflow!");
			else printf( "%lld\n", fact[n] );
		}
	}
	
	return 0;
}