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

int max(int a, int b) { return a > b ? a : b; }
int min(int a, int b) { return a < b ? a : b; }

int solution(int* nums, int numsSize) {
    if (numsSize == 0) return 0;
    
    // Find maximum subarray sum using Kadane's algorithm
    int maxEndingHere = nums[0], maxSoFar = nums[0];
    for (int i = 1; i < numsSize; i++) {
        maxEndingHere = max(nums[i], maxEndingHere + nums[i]);
        maxSoFar = max(maxSoFar, maxEndingHere);
    }
    
    // Find minimum subarray sum using modified Kadane's algorithm
    int minEndingHere = nums[0], minSoFar = nums[0];
    for (int i = 1; i < numsSize; i++) {
        minEndingHere = min(nums[i], minEndingHere + nums[i]);
        minSoFar = min(minSoFar, minEndingHere);
    }
    
    // Return maximum of absolute values
    return max(maxSoFar, abs(minSoFar));
}

int main() {
    char line[10000];
    fgets(line, sizeof(line), stdin);
    
    // Parse array
    int nums[1000];
    int numsSize = 0;
    
    char* token = strtok(line, "[,]");
    while (token != NULL) {
        if (strlen(token) > 0 && token[0] != '\n' && token[0] != ']') {
            nums[numsSize++] = atoi(token);
        }
        token = strtok(NULL, "[,]");
    }
    
    int result = solution(nums, numsSize);
    printf("%d\n", result);
    
    return 0;
}