# Given an array of ints, return True
# if the sequence of numbers 1, 2, 3
# appears in the array somewhere.
#
#
# array123([1, 1, 2, 3, 1]) → True
# array123([1, 1, 2, 4, 1]) → False
# array123([1, 1, 2, 1, 2, 3]) → True

def array123(arr):

    for i in range(len(arr)):
        if arr[i:i+3] == [1, 2, 3]:
            return True
    return False


print(array123([1,1,3,1,2]))
