// Author : MohamedSameh
#include <bits/stdc++.h>
typedef long long ll ;
#define pb push_back
#define f first
#define s second
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()
#define SZ(a) (int)a.size()
#define IN(n) scanf("%d" , &n )
#define debug(x) cout<<#x<<" = { "<<x<<" }\n"
void fo (){fflush(stdout);}
using namespace std;
int n ;
int ans ;
int main ()
{
scanf ("%d" , &n );
for (int i=0,j;i<n;i++)
{
  scanf ("%d" , &t );
  ans += t-1;
}
printf ("%d\n" ,ans ); 
cerr << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
  return 0;
}
