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

long long maximumSubarraySum(int* nums, int numsSize, int k) {
    long long maxSum = 0;
    
    // Check each possible window of size k
    for (int i = 0; i <= numsSize - k; i++) {
        int seen[100001] = {0}; // Assuming values are within reasonable range
        long long currentSum = 0;
        int allDistinct = 1;
        
        // Check current window
        for (int j = i; j < i + k; j++) {
            if (seen[nums[j] + 50000]) { // Offset for negative numbers
                allDistinct = 0;
                break;
            }
            seen[nums[j] + 50000] = 1;
            currentSum += nums[j];
        }
        
        if (allDistinct && currentSum > maxSum) {
            maxSum = currentSum;
        }
    }
    
    return maxSum;
}

int main() {
    char line[10000];
    fgets(line, sizeof(line), stdin);
    
    int nums[1000];
    int count = 0;
    char* token = strtok(line, " ");
    while (token != NULL) {
        nums[count++] = atoi(token);
        token = strtok(NULL, " ");
    }
    
    int k;
    scanf("%d", &k);
    
    printf("%lld\n", maximumSubarraySum(nums, count, k));
    return 0;
}