#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
int main() {
    int n;
    scanf("%d", &n);
    if (n < 0) {
        printf("Invalid input\n");
        return 0;
    }
    char initials[100];
    int even_sum = 0, odd_sum = 0;
    char *ptr = initials;
    for (int i = 0; i < n; i++) {
        scanf(" %c", ptr); 
        if (!isalpha(*ptr)) {
            printf("Invalid input\n");
            return 0;
        }
        int ascii = (int)(*ptr);
        if (ascii % 2 == 0)
            even_sum += ascii;
        else
            odd_sum += ascii;
        ptr++; 
    }
    int char = abs(even_sum - odd_sum);
    printf("%d\n", diff);
    return 0;
}