#include <bits/stdc++.h>

#define int long long
#define MOD 1000000007

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define RFOR(i, a, b) for (int i = (b)-1; i >= (a); i--)
#define rep(i, n) for (int i = 0; i < (n); i++)
#define rep1(i, n) for (int i = 1; i < (n); i++)
#define rrep(i, n) for (int i = (n)-1; i >= 0; i--)
#define all(i) (i).begin(), (i).end()
#define rall(i) (i).begin(), (i).end(), greater<int>()
using namespace std;

#define elif else if
#define eb emplace_back
#define pb push_back
#define mp make_pair
#define fst first
#define sec second
template <typename T>
void print(T x)
{
    std::cout << x << '\n';
}

//typedef long long ll;
#define TENNINE 1000000005
#define TENFIVE 100005
//#define int long long

int N;
vector<int> a;

signed main()
{
    cin >> N;
    a.resize(N);

    rep(i,N){
        cin>>a[i];
    }

    int m=0;
    reo(i,N){
        m+=a[i]-1;
    }
    
    cout <<m<<endl;


    
    return 0;
}
