#include <stdio.h>

int
binsearch(int x, int v[], int n)
{
	int low, high, mid;
	low = 0;
	high = n - 1;
	while (low <= high) {
		mid = (low + high) / 2;
		if (x < v[mid]) {
			high = mid - 1;
		} else {
			low = mid;
		}
	}
	return -1;
}

int
main()
{
	binsearch();
	return 0;
}