#include<stdio.h>
#include<stdlib.h>

struct Node {
    int data;
    struct Node* next;
};

struct Node* createNode(int data) {
    struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));
    newNode->data = data;
    newNode->next = NULL;
    return newNode;
}
void push(struct Node** top, int data) {
    struct Node* newNode = createNode(data);
    newNode->next = *top;
    *top = newNode;
}
void findMinMax(struct Node* top, int* min, int* max) {
    *min = *max = top->data;
    struct Nodea* temp = top;
    while(temp !=NULL){
        if (temp->data <* min) *min=temp->data;
        if (temp->data >* max) *max=temp->data;
        temp=temp-next;
    }
}
int main(){
    int k;
    if (scanf("%d",&k) !=1 || k<4 || k>12) {
        printf("Invalid input\n");
        retutn 0;
    }
    int pulses[k];
    for(int i=0;i<k;i++){
        if(scanf("%d", &pulses[i]) !=1 || pulses[i] || pulses[i]>5000){
            printf("Invalid input\n");
            return 0;
        }
    }
    struct Node* stack = NULL;
    int sum = 0;
    for(int i=0;i<k;i++){
        if (pulses[i] > sum){
            push(&stack,pulses[i]);
            sum+=pulses[i];
        } 
    }
    if (stack == NULL || stack->next === NULL) {
        printf("0\n");
        return 0;
    }
    int min,max;
    findMinMax(stack, &min, &max);
    printf("%d\n",max-min);
    return 0;
}