#include <iostream>
#include <cstdint>
#include <vector>

using namespace std;

int main() {
	int n, c;
	vector<int> lights;
	vector<bool> colors;
	int colors_found = 0;

	cin >> n >> c;

	lights.resize(n);
	colors.resize(c);

	for (int& li : lights) {
		cin >> li;
	}

	int r = 0;
	while (colors_found != c) {
		if (!colors[lights[r]]) colors_found++;

		colors[lights[r]] = true;

		r++;
	}

	colors_found = 0;
	int l = r;
	colors.clear();
	colors.resize(c);
	while (colors_found != c) {
		if (!colors[lights[l]]) colors_found++;

		colors[lights[l]] = true;

		l--;
	}

	cout << r - l - 1;

	return 0;
}