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

int solution(int* nums, int numsSize, int l, int r) {
    // Build prefix sum array
    long long* prefix = (long long*)calloc(numsSize + 1, sizeof(long long));
    for (int i = 0; i < numsSize; i++) {
        prefix[i + 1] = prefix[i] + nums[i];
    }
    
    long long minSum = LLONG_MAX;
    
    // Try each valid window size
    for (int size = l; size <= r; size++) {
        // Slide window of this size across array
        for (int i = 0; i <= numsSize - size; i++) {
            // Calculate sum of window [i, i+size-1]
            long long windowSum = prefix[i + size] - prefix[i];
            
            // Update minimum if sum is positive
            if (windowSum > 0) {
                minSum = (windowSum < minSum) ? windowSum : minSum;
            }
        }
    }
    
    free(prefix);
    return minSum == LLONG_MAX ? -1 : (int)minSum;
}

int main() {
    char line[10000];
    fgets(line, sizeof(line), stdin);
    
    // Parse array
    int nums[1000];
    int numsSize = 0;
    char* token = strtok(line, "[,]");
    while (token != NULL) {
        if (strlen(token) > 0 && token[0] != '\n') {
            nums[numsSize++] = atoi(token);
        }
        token = strtok(NULL, "[,]");
    }
    
    int l, r;
    scanf("%d", &l);
    scanf("%d", &r);
    
    int result = solution(nums, numsSize, l, r);
    printf("%d\n", result);
    
    return 0;
}