#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>

int fact (int n)
{
    if (n==0) return 1;
    else 
        return (n*fact(n-1));
}

int main(){
    int n; 
    int count;
    int max_c;
    int i;
    
    max_c = 0;
    scanf("%d",&n);
    int *m = malloc(sizeof(int) * n);
    for(int m_i = 0; m_i < n; m_i++){
       scanf("%d",&m[m_i]);
    }
    // your code goes here
    i = 1;
    while (i < n)
    {
        max_c += (fact(n) / ((fact(i) * fact(n - i))));
        i++;
    }
      printf("%d", max_c - (n - 1));
     
    return 0;
}