nrnot

#include <fstream>
using namespace std;

int main()
{
    int n,x,y,c;
    ifstream f("nrnot.in");
    f>>n>>x;
    c=n-x;
    while(f>>y)
    {
        if(x!=y)
            c+=x-y-1;
        x=y;
    }
    c+=y-1;
    ofstream g("nrnot.out");
    g<<c;
    return 0;
}