#include<bits/stdc++.h>
using namespace std;
#define el "\n"
#define ll long long
#define ull unsigned long long
#define se second
#define fi first
#define be begin()
#define en end()
#define Faster cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);

int main()
{
    Faster;
    int n; cin >> n;
    int a[n];
    for(auto &x : a) cin >> x;
    int ans = INT_MIN, id1, id2;
    for(int i = 1; i < n; i++)
    {
        if(ans < a[i] - a[i-1])
        {
            ans = a[i] - a[i-1];
            id1 = i-1;
            id2 = i;
        }
    }
    for(int i = 2; i < n; i++)
    {
        if(ans < a[i] - a[i-2])
        {
            ans = a[i] - a[i-2];
            id1 = i - 2;
            id2 = i;
        }
    }
    cout << ans;
    return 0;
}