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

int maxSum = 0;

void generatePairings(int* arr, int arrSize, int pairs[][2], int pairCount) {
    if (arrSize == 0) {
        int currentSum = 0;
        for (int i = 0; i < pairCount; i++) {
            currentSum += (pairs[i][0] < pairs[i][1]) ? pairs[i][0] : pairs[i][1];
        }
        maxSum = (currentSum > maxSum) ? currentSum : maxSum;
        return;
    }
    
    int first = arr[0];
    for (int i = 1; i < arrSize; i++) {
        pairs[pairCount][0] = first;
        pairs[pairCount][1] = arr[i];
        
        int remaining[20];
        int remainingSize = 0;
        for (int j = 1; j < arrSize; j++) {
            if (j != i) {
                remaining[remainingSize++] = arr[j];
            }
        }
        
        generatePairings(remaining, remainingSize, pairs, pairCount + 1);
    }
}

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

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