# Missing Int

# Given an input file with four billion non-negative integers, provide an 
    # algorithm to generate an integer that is not contained in the file.
# Assume you have 1gb of memory for this task.

# FOLLOW-UP:  What if you only have 10mb of memory? 
    # Assume that all the values are distinct and we now have no more than 
        # 1 billion non-negative integers.
        


# time complexity:  O()
# space complexity:  O()
