#include <fstream.h>

#define input "culori.in"
#define output "culori.out"
#define dimmax 10000

long n,a[dimmax];

int main()
{
        ifstream fin(input);
        ofstream fout(output);
        fin>>n;
        int i,m;
        i=1;
        while(fin>>a[i])
          i++;
        m=i-1;
          
        if(a[1]!=a[m])
           fout<<0;
           
        else
        {
           fout<<n;  
        }
        return 0;
}