#include <bits/stdc++.h>
using namespace std;
#define ll long long

int main(){
  int N;
  cin>>N;
  int a[N];
  ll int m,ans=0;
  int cou=1,mx=0;
  ll int r,tmp,b,c,x;

  for(int i=0;i<N;i++)cin>>a[i];
  for(int i=0;i<N;i++)ans+=a[i]-1
  cout<<ans<<endl;
}