Untitled

#include<iostream>
using namespace std;
int main()
{  
    int n,m,ticket;
    while(1)
    {
        int dubli=0,check[10001]={0};
        cin>>n>>m;
        if(n == 0 && n ==0 )
        {
            break;
        }
        for(int i =0;i<m;i++)
        {
            cin>>ticket;
            check[ticket]++;
        }
        for(int j =1;j<=n;j++)
        {
          if(check[j]>1)
          {
            dubli++;
          }
        }
        cout<<dubli<<endl;
        

    }
    return 0;
}