oneday-2

标题 oneday-2
George has recently entered the BSUCP (Berland State University for Cool Programmers). George has a friend Alex who has also entered the university. Now they are moving into a dormitory.

George and Alex want to live in the same room. The dormitory has n rooms in total. At the moment the i-th room has pi people living in it and the room can accommodate qi people in total (pi ≤ qi). Your task is to count how many rooms has free place for both George and Alex.

Input
The first line contains a single integer n (1 ≤ n ≤ 100) — the number of rooms.

The i-th of the next n lines contains two integers pi and qi (0 ≤ pi ≤ qi ≤ 100) — the number of people who already live in the i-th room and the room’s capacity.

Output
Print a single integer — the number of rooms where George and Alex can move in.

Examples
Input
3
1 1
2 2
3 3
Output
0
Input
3
1 10
0 10
10 10
Output
2
问题简述：输入n个房间，第i个房间已入住人数为pi,可容纳人数为qi，George 和Alex要住同一个房间，有多少房间可供他们选择？

在这里插入代码片
```#include <iostream>
using namespace std;
int main()
{
	int n, i;
	int sum = 0;
	int p[100], q[100];
	cin >> n;
	for (i = 0; i < n; i++)
	{
		cin >> p[i] >> q[i];
		if ((q[i] - p[i]) >= 2)
		{
			sum++;
		}
		cout << endl;
	}
	cout << sum;
	return 0;
}