#include<bits/stdc++.h> using namespace std; int main() { int n,x1,x2,s1=0,s2=0; cin>>n; for(int i=1;i<=n;i++) { cin>>x1>>x2; if(x1>=90&&x1<=140&&x2>=60&&x2<=90) { s1+=1; } else { s1=0; } s2=max(s2,s1); } printf("%d",s2); }