第二题

#include <iostream>
using namespace std;
int main()
{
 int n, a[100][2], b = 0;
 cin >> n;
 for (int t = 0; t < n; t++)
 {
  cin >> a[t][0] >> a[t][1];
 }
 for (int t = 0; t < n; t++)
 {
  if (a[t][0] <= (a[t][1] - 2))b++;
 }
 cout << b << endl;
 system("pause");
}