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

struct TreeNode {
    int val;
    struct TreeNode* left;
    struct TreeNode* right;
};

struct TreeNode* createNode(int val) {
    struct TreeNode* node = (struct TreeNode*)malloc(sizeof(struct TreeNode));
    node->val = val;
    node->left = NULL;
    node->right = NULL;
    return node;
}

int dfs(struct TreeNode* node, struct TreeNode* parent, struct TreeNode* grandparent) {
    if (!node) return 0;
    
    int result = 0;
    if (grandparent && grandparent->val % 2 == 0) {
        result += node->val;
    }
    
    result += dfs(node->left, node, parent);
    result += dfs(node->right, node, parent);
    
    return result;
}

int solution(struct TreeNode* root) {
    return dfs(root, NULL, NULL);
}

struct TreeNode* buildTree(int* arr, int size) {
    if (size == 0 || arr[0] == -1001) return NULL;
    
    struct TreeNode* root = createNode(arr[0]);
    struct TreeNode* queue[1000];
    int front = 0, rear = 0;
    queue[rear++] = root;
    int i = 1;
    
    while (front < rear && i < size) {
        struct TreeNode* node = queue[front++];
        
        if (i < size && arr[i] != -1001) {
            node->left = createNode(arr[i]);
            queue[rear++] = node->left;
        }
        i++;
        
        if (i < size && arr[i] != -1001) {
            node->right = createNode(arr[i]);
            queue[rear++] = node->right;
        }
        i++;
    }
    
    return root;
}

int main() {
    char line[10000];
    fgets(line, sizeof(line), stdin);
    
    int arr[1000];
    int size = 0;
    char* token = strtok(line, "[],\n ");
    while (token != NULL) {
        if (strcmp(token, "null") == 0) {
            arr[size++] = -1001;
        } else {
            arr[size++] = atoi(token);
        }
        token = strtok(NULL, "[],\n ");
    }
    
    struct TreeNode* root = buildTree(arr, size);
    printf("%d\n", solution(root));
    
    return 0;
}