#include<bits/stdc++.h>

using namespace std;

int date[12] = {31,29,31,30,31,30,31,31,30,31,30,31};
int main(){
    int N;
    cin >> N;
    int month[N],day[N];
    for(int i = 0;i < N;i++){
        cin >> month[i] >> day[i];
    }
    int maxx = -1;
    int ans;
    for(int i = 0;i < N - 1;i++){
        ans = 0;
        for(int j = month[i];j < month[i + 1];j++){
            if(j > month[i] && j < month[i + 1]){
                ans += date[j];
            }else if(j == month[i]){
                ans += (date[j] - day[i]);
            }else{
                ans += (day[i + 1] - 1);
            }
        }
        maxx = max(maxx,ans);
    }
    cout << round(maxx * 86400 / 366) << endl;
    return 0;
}