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

int main(){
    int n;
    char arr[100];
    int evenSum = 0, oddSum = 0;
    
    scanf("%d" , &n);
    
    if (n <1 || n> 100) {
        printf("Invalid input\n");
        return 0;
    }
    
    for(int i = 0; i < n;i++) {
        scanf(,  &arr[i]);
        if (!isalpha(arr[i]);
        printf("Invalid input\n");char *ptr = arr;
         return 0;
    }
}

for (int i = 0; i < n; i++){
    int ascii = *(ptr + i){
        if (ascii % 2 ==0)
        evenSum += ascii;
        else
        oddSum += ascii;
    }
    
    printf("%d\n", abs(evensum - oddSum));
    
    return 0;
    }