#include <vector>
#include <cstring>
#include <iostream>
using namespace std;
const int N = 100005, M = 50005, INF = 0x3f3f3f3f;

int f[N], q[N], g[2][M], len[2][M];

vector<int> d[N];

int minimumInstructions(
    int n, int m, int K, std::vector<int> c,
    std::vector<int> a, std::vector<std::vector<int> > b) {
  	memset(f, 0x3f, sizeof f);
  	memset(g, -1, sizeof g);
  	for (int i = 0; i < K; i++) d[i].clear();
  	for (int i = 0; i < m; i++) {
  		for (int j = 0; j < a[i]; j++) {
  			d[b[i][j]].push_back(i);
  		}
  	}
  	int hh = 0, tt = -1;
  	for (int i = 0; i < n; i++) {
  		bool ok = false;
  		for (int j = 0; j < d[c[i]].size(); j++) {
  			int u = d[c[i]][j];
  			g[i & 1][u] = i, len[i & 1][u] = 1;
  			if (i && g[(i - 1) & 1][(u + m - 1) % m] == i - 1) len[i & 1][u] += len[(i - 1) & 1][(u + m - 1) % m];
  			if (len[i & 1][u] >= m) ok = true;
  		}
  		if (ok) {
  			while (hh <= tt && q[hh] < i - m) hh++;
  			if (i < m) f[i] = 1;
  			else if (hh <= tt) f[i] = f[q[hh]] + 1;
  			if (f[i] != INF) {
  				while (hh <= tt && f[q[tt]] >= f[i]) tt--;
            	q[++tt] = i;
  			}
  		}
  	}
  	return f[n - 1] == INF ? -1 : f[n - 1];
}