#include <iostream>
using namespace std;
 
int main() {
    int n;
    long long factorial = 1; // Using long long for handling larger values
 
    cout << "Enter a non-negative integer: ";
    cin >> n;
 
    if (n < 0) {
        cout << "Factorial is not defined for negative numbers." << endl;
    } else {
        for (int i = 1; i <= n; ++i) {
            factorial *= i; // Multiplying with each number up to n
        }
        cout << "Factorial of " << n << " = " << factorial << endl;
    }
 
    return 0;
}

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