import java.math.BigInteger;
import java.util.Arrays;
public class CombinationCalculator {
public static BigInteger calculateCombination(int n, int k) {
BigInteger numerator = factorial(n);
BigInteger denominator = factorial(k).multiply(factorial(n - k));
return numerator.divide(denominator);
}
private static BigInteger factorial(int num) {
BigInteger result = BigInteger.ONE;
for (int i = 1; i <= num; i++) {
result = result.multiply(BigInteger.valueOf(i));
}
return result;
}
public static void main(String[] args) {
int n = 5;
int k = 2;
BigInteger combination = calculateCombination(n, k);
System.out.println("C(" + n + ", " + k + ") = " + combination);
}
}
