#include <iostream>

#define RPT(i, n) for (int i = 0; i < n; i++)

using namespace std;

// ABC103-C - Modulo Summation
int main()
{
    int N;
    vector<int> a;

    cin >> N;
    RPT(i, N) {
        int tmp;
        cin >> tmp;
        a.push_back(tmp);
    }

    int ans = 0;
    RPT(i, N) ans += a[i];
    ans -= N;

    cout << ans << endl;

    return 0;
}
