def even(x: Int) : Boolean = 
    toInt(toChar(x * 128)) == 0;
def pow(x: Int, y: Int): Int =
    if (y == 0) 1
    else if (even(y)) {
        val t = pow(x, y / 2);
        t*t 
    } else {
    x * pow(x, y - 1)
    };
var i = 30; var res = 0;

while(i > 0) {
    res = res + pow(2, i);
    i = i - 1; ()
};
res