#include <stdio.h>
#include<ctype.h>
int main()
{
    int n;
    scanf("%d",&n);
    char str[n];
    fgets(str,sizeof(str),stdin);
    int minChar; 
    int maxChar;
    for(int i=0;str[i]!='\0';i++)
    {
        if(isdigit(str[i]))
        {
            printf("Invalid input");
            return 0;
        }
    }
    for (int i = 1; str[i] != '\0'; i++) {
        if (str[i]%2==0) 
        {
            minChar = str[i];  
        }
        if (str[i]%2!=0) 
        {
            maxChar = str[i];  
        }
    }
    printf("%d", abs(minChar-maxChar));
    return 0;
}