#include<stdio.h>

int main()
{
   int i;
   int n;
   scanf("%d", &n);
   int R[n];

   for(i=0; i<n; i++){
      scanf("%d", &R[i]);
   }

   int min = R[0];
   int max = R[1]-R[0];

   for(i=1; i<n; i++){
      max = (max<(R[i]-min)) ? (R[i]-min) : max;
      min = (min>R[i]) ? R[i] : min;
   }

   printf("%d\n", max);

   return 0;
}