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

typedef struct {
    int first, second;
} Pair;

int digitSum(int n) {
    int total = 0;
    while (n > 0) {
        total += n % 10;
        n /= 10;
    }
    return total;
}

int solution(int* nums, int size) {
    Pair pairs[100]; // Assume max 100 different digit sums
    int digitSums[100];
    int numPairs = 0;
    int result = -1;
    
    for (int i = 0; i < size; i++) {
        int ds = digitSum(nums[i]);
        
        // Find existing pair or create new one
        int pairIndex = -1;
        for (int j = 0; j < numPairs; j++) {
            if (digitSums[j] == ds) {
                pairIndex = j;
                break;
            }
        }
        
        if (pairIndex == -1) {
            pairIndex = numPairs++;
            digitSums[pairIndex] = ds;
            pairs[pairIndex].first = nums[i];
            pairs[pairIndex].second = -1;
        } else {
            Pair* p = &pairs[pairIndex];
            if (p->second == -1) {
                p->second = nums[i];
                int sum = p->first + p->second;
                if (sum > result) result = sum;
            } else {
                if (nums[i] > p->first) {
                    p->second = p->first;
                    p->first = nums[i];
                } else if (nums[i] > p->second) {
                    p->second = nums[i];
                }
                int sum = p->first + p->second;
                if (sum > result) result = sum;
            }
        }
    }
    
    return result;
}

int main() {
    char line[10000];
    fgets(line, sizeof(line), stdin);
    line[strcspn(line, "\n")] = 0;
    
    int nums[1000];
    int size = 0;
    char* token = strtok(line + 1, ",]");
    
    while (token != NULL) {
        nums[size++] = atoi(token);
        token = strtok(NULL, ",]");
    }
    
    int result = solution(nums, size);
    printf("%d\n", result);
    
    return 0;
}