#include <iostream>
#include <vector>
using namespace std;
#include <queue>
int main() {
    int m, n;
    cin >> m >> n;

    queue<int> queue;

    vector<int> shuzu(n);
    for (int i = 0; i < n; i++) {
        cin >> shuzu[i];
    }

    int miss = 0;
    vector<int> jilu(1001);
    for (int i = 0; i < jilu.size(); i++) {
        jilu[i] = 0;
    }

    for (int i = 0; i < shuzu.size(); i++) {
        if (jilu[shuzu[i]] < 1) {
            if (queue.size() < m) {
                queue.push(shuzu[i]);
                jilu[shuzu[i]] = 1;
                miss++;
            } 
            else {
                int qingling = queue.front();
                jilu[qingling] = 0;
                queue.pop();
                queue.push(shuzu[i]);
                jilu[shuzu[i]] = 1;
                miss++;
            }
            continue;
        } 
        else {
            continue;
        }
    }

    cout << miss << endl;
    return 0;
}
// 64 位输出请用 printf("%lld")