import java.math.BigInteger;

import java.util.Scanner;

public class Big {

public static void main(String[] args) {

// int startNum = askUserForInteger();

// int endNum = factorial(startNum);

for (int i = 0; i <= 30; i ++) {

factorial(i); // over ~15 these values get wonky because they get too big for the int data type

} // I think BigInteger is mutable because I can construct a new BigInteger and set the attribute

}

public static BigInteger factorial(int x) {

int result = 1;

BigInteger bigResult = BigInteger.valueOf(result);

for (int i = x; i > 0; i--) {

BigInteger counter = BigInteger.valueOf(i);

bigResult = bigResult.multiply(counter);

}

System.out.println(x + "! = " + bigResult);

return bigResult;

}

}