def BinarySearch(l,key):
low=0
high=len(l)-1
i=0
while(low <= high):
i = i+1
mid = low + ((high-low)>>1)
if(l[mid] < key):
low = mid + 1
elif (l[mid] > key):
high = mid -1
else:
print "use %d times" % i
return mid
return -1
if __name__ == "__main__":
l=[1,4,5,6,7,8,9,44,333,2233]
print l
print BinarySearch(l,4)
print BinarySearch(l,44)
print BinarySearch(l,8)
print BinarySearch(l,2233)
print BinarySearch(l,77)