Model2020MIs3e3.cpp

#include <iostream>
#include <fstream>
using namespace std;

int main() {

	ifstream f("numere.in");
	int n, x, count = 0;

	f >> n;

	while (f >> x) {
		if (n > x) {
			count += n - x;
		}
		n = x - 1;
	}


	count += n;
	cout << count << endl;



	return 0;
}