#include<cstdio>

int n,a[1100],i,s,b,c,max;

int main()

{
    scanf("%d", &n);
    
    for(i=1; i<=n; ++i)
    scanf("%d", &a[i]);
    
    b=a[1];
    
    for(i=1; i<=n; ++i){

    if (a[i]<a[i+1]) {s=a[i+1]; c=s-b;} else b=a[i+1];
    
    if (c>max) max=c;
 
}

printf("%d", max);


return 0;

}