def linearna_pretraga(a, x):
    n = len(a)
    for i in range(n):
        if a[i] == x:
            return i
    return -1

def binarna_pretraga1(a, x):
    l = 0
    r = len(a) - 1
    while l <= r:
        mid = l + (r - l) // 2;
        if a[mid] == x:
            return mid
        elif a[mid] < x:
            l = mid + 1
        else:
            r = mid - 1
    return -1
	
def binarna_pretraga2(a, l, r, x):
    if r >= l:
        mid = l + (r - l) // 2
        if a[mid] == x:
            return mid
        elif a[mid] > x:
            return binarna_pretraga2(a, l, mid - 1, x)
        else:
            return binarna_pretraga2(a, mid + 1, r, x)
    else:
        return -1