pos = -1

def Search(list,n):

    l = 0
    u = len(list)-1	
    while l <= u:
        mid = (l+u)//2
        if list[mid] == n:
            globals()['pos'] = mid
            return True
        else:
            if list[mid] < n:
                l = mid+1
            else:
                u = mid-1
    return False


list = [1,3,7,9,23,65,88,453,2290,767654]
n = 453

if Search(list,n):
    print("found at",pos+1)
else:
    print("not found")