MAIN8_B - Overlapping Squares
you are given N (1<=N<=20000) squares on X-Y plane. Your task is to find the area which is common to all the squares (Area of intersection of all the squares)
First line contain T the number of test cases. Then T test cases follow. First line of each test case contains N, the number of squares Each of following N line contains 3 integer (X, Y, L) cordinate of lower left vertex and size of the square.
For each test case print the answer in a new line.
Input: 2 2 0 0 10 1 1 11 2 10 10 25 1 1 3 Output: 81 0