SumTimeCheat.java

/**
 * Created by olegchir on 18.11.2016.
 */
import java.math.BigInteger;

class Sum2 {
    private static final BigInteger MIN = BigInteger.ONE;
    private static final BigInteger MAX = new BigInteger("10000000000");
    private static final BigInteger TWO = new BigInteger("2");

    public static void main(String[] args) {
        long startTime = System.currentTimeMillis();
        final BigInteger result = (MIN.add(MAX)).multiply(MAX.divide(TWO)); //Hi from mister Gauss, motherfuckers!
        long endTime = System.currentTimeMillis();

        System.out.println(String.format("Result: %s", result.toString()));
        System.out.println(String.format("Execution time: %d milliseconds", endTime - startTime));
    }
}