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

int main() {
    int n;
    if (scanf("%d", &n) != 1 || n < 0) {
        printf("Invalid input\n");
        return 0;
    }

    char ch;
    int even_sum = 0, odd_sum = 0;

    for (int i = 0; i < n; i++) {
        if (scanf(" %c", &ch) != 1 || !isalpha(ch)) {
            printf("Invalid input\n");
            return 0;
        }

        int ascii = (int)ch;
        if (ascii % 2 == 0)
            even_sum += ascii;
        else
            odd_sum += ascii;
    }

    printf("%d\n", abs(even_sum - odd_sum));
    return 0;
}

#include<stdio.>
#include<cty
void main()
{
    int a;
    scanf("%d",&a);
    printf("%p",a);
}


#include<stdio.h>
void main(){
    cha
}