#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int main()
{
    freopen("heaven.in","r",stdin);
    freopen("heaven.out","w",stdout);
    int day[12]={0,31,60,91,121,152,182,213,244,274,305,335};
    int n,month,days;
    cin>>n;
    if(n==0)
    {
		cout<<86400<<endl;
		return 0;
    }
	int a[n],b[n+1];
    for(int i=0;i<n;i++)
    {
		cin>>month>>days;
		a[i]=day[month-1]+days;
    }
    sort(a,a+n);
    b[0]=a[0]-1;
    b[n]=366-a[n-1];
    for(int i=1;i<n;i++)
		b[i]=a[i]-a[i-1]-1;
    int maxn=0;
    for(int i=0;i<=n;i++)
		if(maxn<b[i])
			maxn=b[i];
    double maxm=(maxn/366.0)*24.0*3600.0;
    int k=maxm+0.5;
    cout<<k<<endl;
    return 0;
}