public boolean modest() {
if (a.length < 1) return false;
Quicksort.Quicksort(a, 0, a.length - 1);
boolean isExist = false;
for (int i = 1; i < a.length; i++) {
isExist = Binarysearch.Binarysearch(a, sum - a[i], i + 1, a.length - 1);
if (isExist == true) {
return isExist;
}
}
return isExist;
}
