#include <cstdio>

const int MAXN=1001;
int n, p[MAXN];

int main(){
	int poc=0, kraj=0, max=0;
	scanf ("%d", &n);
	for (int i=0; i<n; ++i)
		scanf ("%d", &p[i]);
	for (int i=1; i<n; ++i){
		if (p[i]>p[i-1]){
			poc=i-1;
			kraj=i;
			for(++i;i<n; ++i)
				if (p[i]>p[i-1])
					kraj=i;
				else break;		
		}
		if (p[kraj]-p[poc]>max) max=p[kraj]-p[poc];
	}	
	printf ("%d", max);
	//scanf ("%*c%*c");
	return 0;
}