A. George and
Accommodation
time
limit per test 1 second
memory
limit per test 256 megabytes
input
standard input
output
standard output
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
Solution
- [tab]
- C++
#include<iostream> using namespace std; int main() { int n,x,y,count=0; cin>>n; for(int i=1;i<=n;i++) { cin>>x>>y; if((y-x)>=2) count++; } cout<<count<<endl; return 0; }
