#include <iostream>

using namespace std;

struct Tree
{
    int num;
    Tree* Left;
    Tree* Right;
    Tree(int x) : num(x), Left(NULL), Right(NULL) { }
};

int add(Tree* &t, int num)
{
    if (!t)
    {
        t = new Tree(num);
        return 1;
    }
    if (t->num == num) return 0;
    if (t->num > num) return add(t->Left, num);
    return add(t->Right, num);
}

int main()
{
    Tree* tr = NULL;
    int ans = 0;
    int n;
    cin >> n;
    while (n)
    {
        ans += add(tr, n);
        cin >> n;
    }
    cout << ans << endl;
    return 0;
}