data = [28,3,9,14,7,42,21,36]
target = 3
data.sort()

def binary(data,target):
    left = 0
    right = len(data)-1
    while left<=right:
        mid = (left+right)//2
        if data[mid] == target:
            return True
        elif data[mid]<target:
            left = mid + 1
        else:
            right = mid - 1
    return False
print(binary(data, target))