public class Assert2 {
     // pre : y >= 0
     // post: returns x^y
     public static int pow(int x, int y) {
         int prod = 1;
         // Point A
         while (y > 0) {
             // Point B
             if (y % 2 == 0) {
                 // Point C
                 x = x * x;
                 y = y / 2;
                 // Point D
             } else {
                 // Point E
                 prod = prod * x;
                 y--;
                 // Point F
             }
             // Point G
         }
         // Point H
         return prod;
     }
}
/*

   Assume the method is called only if the precondition is true.  Fill in the
   table below with the words ALWAYS, NEVER or SOMETIMES.

                    y == 0              y % 2 == 0       
            +---------------------+---------------------+
    Point A | sometimes           | sometimes           |
            +---------------------+---------------------+
    Point B | never               | sometimes           |
            +---------------------+---------------------+
    Point C | never               | always              |
            +---------------------+---------------------+
    Point D | never               | sometimes           |
            +---------------------+---------------------+
    Point E | never               | never               |
            +---------------------+---------------------+
    Point F | sometimes           | always              |
            +---------------------+---------------------+
    Point G | sometimes           | sometimes           |
            +---------------------+---------------------+
    Point H | always              | always              |
            +---------------------+---------------------+
            
*/