#include<bits/stdc++.h>
using namespace std;
const int N=110;
int a[N],b[N],ans[N];
bool cmp(int x,int y){
return x>y;
}
int main(){
int n;
cin>>n;
for(int i=1;i<=n;i++){
cin>>a[i]>>b[i];
}
int k=1;
for(int i=1;i<=n;i++){
if(a[i]>=90&&a[i]<=140&&b[i]>=60&&b[i]<=90) ans[k]++;
else k++;
}
sort(ans+1,ans+1+k,cmp);
cout<<ans[1];
return 0;
}