time limit per test: 0.25 sec. memory limit per test: 4096 KB

Along the border between states A and B there are N defence outposts. For every outpost k, the interval [A_{k},B_{k}] which is guarded by it is known. Because of financial reasons, the president of country A decided that some of the outposts should be abandoned. In fact, all the redundant outposts will be abandoned. An outpost i is redundant if there exists some outpost j such that A_{j}<A_{i} and B_{i}<B_{j}. Your task is to find the number of redundant outposts.

Input

The first line of the input will contain the integer number N (1<=N<=16 000). N lines will follow, each of them containing 2 integers: A_{k} and B_{k} (0<= A_{k} < B_{k} <= 2 000 000 000), separated by blanks. All the numbers A_{k }will be different. All the numbers B_{k} will be different.

Output

You should print the number of redundant outposts.