#include<fstream>
using namespace std;
int n;
int v[1000000],p[1000000];
long long nr;
int main()
{
    ifstream fin("operatii.in");
    ofstream fout("operatii.out");
    fin>>n;
    int i;
    for(i=1;i<=n;i++)
     fin>>v[i];
    int j;
    for(i=1;i<=n;i++)
      if(v[i]!=0 && p[i]!=v[i])   
       { 
        nr++;
        for(j=i+1;j<=n && v[j]!=0;j++)
          if(p[j]!=v[i])
             p[j]=v[i];
       }
   fout<<nr;             
    return 0;
}