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

int minMaxSum = INT_MAX;

void generatePairings(int* available, int availableSize, int pairs[][2], int pairCount) {
    if (availableSize == 0) {
        int maxSum = 0;
        for (int i = 0; i < pairCount; i++) {
            int sum = pairs[i][0] + pairs[i][1];
            if (sum > maxSum) maxSum = sum;
        }
        if (maxSum < minMaxSum) minMaxSum = maxSum;
        return;
    }
    
    int first = available[0];
    for (int i = 1; i < availableSize; i++) {
        int partner = available[i];
        
        int newAvailable[20];
        int newSize = 0;
        for (int j = 1; j < availableSize; j++) {
            if (j != i) {
                newAvailable[newSize++] = available[j];
            }
        }
        
        pairs[pairCount][0] = first;
        pairs[pairCount][1] = partner;
        generatePairings(newAvailable, newSize, pairs, pairCount + 1);
    }
}

int solution(int* nums, int numsSize) {
    minMaxSum = INT_MAX;
    int pairs[10][2];
    generatePairings(nums, numsSize, pairs, 0);
    return minMaxSum;
}

int main() {
    char line[1000];
    fgets(line, sizeof(line), stdin);
    
    int nums[20];
    int size = 0;
    char* token = strtok(line + 1, ",]");
    while (token != NULL) {
        nums[size++] = atoi(token);
        token = strtok(NULL, ",]");
    }
    
    printf("%d\n", solution(nums, size));
    return 0;
}