#include <cstdio>
#include <climits>
int main() {
    int n;
    scanf("%d", &n);
    if (n < 2) {
        printf("0\n");
        return 0;
    }
    int min_val;
    scanf("%d", &min_val);
    int max_diff = INT_MIN;
    for (int i = 1; i < n; ++i) {
        int current;
        scanf("%d", &current);
        
        int diff = current - min_val;
        if (diff > max_diff) {
            max_diff = diff;
        }
        if (current < min_val) {
            min_val = current;
        }
    }
    if (max_diff < 0) {
        max_diff = 0;
    }
    printf("%d\n", max_diff);
    return 0;
}