bac 4/220/2022 3

#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("numere.in");

int main() {
    int n, x1, x2, k = 0;
    fin >> n >> x1;
    k = n - x1;
    while ((fin >> x2)) {
        if (x1 != x2) {
            k += (x1 - x2) - 1;
        }
        x1 = x2;
    }
    k += x2 - 1;
    cout << k << endl;
    return 0;
}