#include using namespace std; int main() { int n,ans=0; cin>>n; int G[n],D[n]; int maxv=-10000; for (int i = 0; i < n; ++i) { cin>>G[i]>>D[i]; if(G[i]-30000*D[i]>maxv){ maxv=max(G[i]-30000*D[i],maxv); ans=i; } } if((G[ans]-30000*D[ans])*6>=3000000){ cout<<"YES"<