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

int main()
{
    int n,sjh,i=1,i2;
    cin>>i2;
    while(i<=i2)
    {
        scanf("%d ",&n);
        sjh=sjh+n;
        i++;
    }
    cout<<sjh-1;
    return 0;
}