#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define mp make_pair
#define eb emplace_back
#define vi vector<int>
#define pii pair<int,int>
#define F first
#define S second
#define f0r(i,n) for(int i = 0; i < n; i++)
#define FOR(i,k,n) for(int i = k; i < n; i++)
#define dout(x) cout<<x<<' '<<#x<<endl
#define dout2(x,y) cout<<x<<' '<<#x<<' '<<y<<' '<<#y<<endl
#define vout(v) for(auto u : v)cout<<u<<' '; cout<<endl
using namespace std;
const int mxn = 1e5 + 5;
int n; pii v[mxn];
signed main(){
cin>>n; f0r(i,n){int x, y; cin>>x>>y; v[i] = {x,y};} int ans = 0; f0r(i,n){if(v[i].F==v[i].S)ans++;} cout<<ans;
}
