public class Demo {
public static void main(String[] args) throws InterruptedException {
long start = System.currentTimeMillis();
long sum = 0;
for (int i = 0; i <= 100000; i++) {
sum += i;
}
System.out.println("sum = " + sum);
long end = System.currentTimeMillis();
System.out.println(end - start + "ms");
}
}