pbinfo_4015_unique

#include <iostream>

using namespace std;

unsigned int u[6251];  /// aici avem 32 x 6251 biti = 200032;  -- daca e aici inseamna ca apare o data
unsigned int v[6251];  /// aici avem 32 x 6251 biti = 200032;  -- daca e si aici atunci apare de mai multe ori
int k;


int getBit(int poz, unsigned int a[]){
    return ((a[poz/32] & (1 << (poz%32)))>0);
}
void setBit(int poz, unsigned int a[]){
    a[poz/32] |= (1 << (poz%32));
}


int main()
{
    while(cin >> k){

        if(getBit(k,u)) {
            setBit(k,v);  /// marchez a doua aparitie (cel putin a doua)
        }
        else
        {
            setBit(k,u); /// imi apare prima oara

        }
    }

    int contor=0;
    for(int i=0; i<200000; i++)
        if(getBit(i,u) && !(getBit(i,v))) contor++;

    cout << contor;
    return 0;
}