50 50 50 50
 49 49 4 1
 48 50 12 11
 5 7 1 10
 1 50 50 50
 5 7 1 4
 32 4 17 3
 1 50 1 50
 50 1 1 1
 32 31 10 9
 5 7 4 1
 49 49 3 3
 50 49 1 2
 50 48 3 1
 50 1 1 50
 5 7 10 10
 1 1 1 1
 49 50 11 12

Second
 Second
 Second
 Second
 Second
 Second
 First
 Second
 First
 First
 Second
 Second
 First
 First
 First
 Second
 Second
 Second

#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, count = 0, a[30], b[30];
  cin >> x;
  int tc = x;
  while (tc--) cin >> a[tc] >> b[tc];
  for (int i = 0; i < x; i++) {
    for (int j = 0; j < x; j++) {
      if (a[i] == b[j]) {
        count++;
      }
    }
  }
  cout << count << endl;
  return 0;
}
