#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(int)(n); i++)



int main(){
    int N; cin >> N;
    bool ans = false;
    rep(i,N){
        int v,w; cin >> v >> w;
        if(w == 1) ans = true;
    }
    cout << (ans ? "Yes" : "No") << endl;
    return 0;
}


struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;