#include <iostream>
#include<bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define INF 0x3f3f3f3f
#define inf 0x3f3f3f3f3f3f3f3f
#define rep(i,a,b) for(auto i=a;i<=b;++i)
#define bep(i,a,b) for(auto i=a;i>=b;--i)
#define lowbit(x) x&(-x)
#define PII pair<int,int>
#define PLL pair<ll,ll>
#define PI acos(-1)
#define pb push_back
#define eps 1e-6
const int mod = 1e9 + 7;
const int MOD = 1e4+7;
const int N = 2e6 + 10;
const int M = 1111;
int dx[]={-1, 0, 1, 0};
int dy[]={0, 1, 0, -1};
int dxy[][2]={{0,1},{1,0},{1,1},{-1,1}};
using namespace std;

int dp[M];

void solve(){
    int n;
    cin>>n;
    rep(i,1,n) cin>>dp[i];
    int maxn=-1;
    rep(i,2,n) maxn=max(maxn,abs(dp[i]-dp[i-1]));
    cout<<maxn<<endl;
}

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    solve();
    return 0;
}