#include<bits/stdc++.h>
using namespace std;
int n;
long long ans = -1e8; 
int a[1000005];
long long dp[1000005];
int main(){
    cin >> n;
    for(int i = 1;i <= n;i++){
    	cin >> a[i];
    }
    dp[1] = 0;
    int p = a[1];
	for(int i = 2;i <= n;i++){
		if(a[i] > p){
			dp[i] = a[i]-p;
		}else{
			p = a[i];
		}
		ans = max(ans,dp[i]);
	}
	cout << ans;
    return 0;
}