- #include <iostream> 
- #include <iomanip> 
- using namespace std; 
-   
- int getNumber() { 
- 	int n; 
- 	do { 
- 		cout << "Enter a non-negative number!\n"; 
- 		cin >> n; 
- 	} while (cin && n < 0); 
- 	return n; 
- } 
-   
- int main() { 
-     int n = getNumber(); 
-     long double factorial = 1; 
-     for (int i = 1; i <= n; ++i) 
-         factorial *= i; 
-     // cout.precision(2); 
-     cout << n << "! = "  << factorial; 
-     return 0; 
- } 
				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