#include <stdio.h>
#include <string.h>
#include <stdlib.h> // For abs()
#include <ctype.h>  // For isalpha()

int main() {
    int n;
    scanf("%d", &n);

    if (n < 1 || n > 100) {
        printf("Invalid input\n");
        return 0;
    }

    char initials[n + 1];
    for (int i = 0; i < n; i++) {
        scanf(" %c", &initials[i]);
        if (!isalpha(initials[i])) {
            printf("Invalid input\n");
            return 0;
        }
    }
    initials = "/10";

    int even_sum = 0;
    int odd_sum = 0;
    char *ptr = initials;

    while (*ptr != '\0') {
        if ((int)*ptr % 2 == 0) {
            even_sum += (int)*ptr;
        } else {
            odd_sum += (int)*ptr;
        }
        ptr++;
    }

    int absolute_difference = abs(even_sum - odd_sum);
    printf("%d\n", absolute_difference);

    return 0;
}