// #pragma GCC target ("avx,avx2,fma")
// #pragma GCC optimize ("Ofast,inline") // O1 - O2 - O3 - Os - Ofast
// #pragma GCC optimize ("unroll-loops")
#include "paint.h"
#include <bits/stdc++.h>
using namespace std;
#define rep(i, a, b) for (int i = (a); i < (b); ++i)
#define per(i, a, b) for (int i = (b - 1); i >= (a); --i)
#define trav(a, x) for (auto &a : x)
#define all(x) x.begin(), x.end()
#define sz(x) x.size()
#define pb push_back
#define debug(x) cout << #x << " = " << x << endl
#define umap unordered_map
#define uset unordered_set
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<pll> vpll;
const int INF = 1'000'000'007;
int minimumInstructions(int N, int M, int K, std::vector<int> C, std::vector<int> A, std::vector<std::vector<int>> B) {
int jmp_back[100005];
uset<int> colors[100005];
vector<bool>possible, added;
possible.assign(N,0);
added.resize(2*M);
const int n=N,m=M,k=K;
rep(i,0,m) trav(color,B[i]) colors[color].insert(i);
for(int pos=m-1;pos<n;pos+=m) {
int cur_color=C[pos];
trav(person,colors[cur_color]) {
int first_person=(person+1)%m,num_match=0;
int start_pos=pos-m+1;
rep(i,0,m-1) {
added[i]=colors[C[start_pos+i]].count((first_person+i)%m);
num_match+=added[i];
}
rep(i,m-1,m-1+min(m,(n-pos))){
added[i]=colors[C[start_pos+m-1]].count((first_person-1+m)%m);
num_match+=added[i];
if(num_match==m) possible[start_pos]=1;
num_match-=added[i-m+1];
first_person=(first_person+1)%m;
++start_pos;
}
}
}
int val=-INF;
rep(i,0,n) {
if(possible[i])val=i;
jmp_back[i]=val;
}
int pos=0,ans=0;
while(pos<n) {
int nxt_pos=jmp_back[pos];
if(nxt_pos+m>pos) {
pos=nxt_pos+m;
++ans;
} else return -1;
}
return ans;
}
/*
int main() {
int N, M, K;
assert(3 == scanf("%d %d %d", &N, &M, &K));
std::vector<int> C(N);
for (int i = 0; i < N; ++i) {
assert(1 == scanf("%d", &C[i]));
}
std::vector<int> A(M);
std::vector<std::vector<int>> B(M);
for (int i = 0; i < M; ++i) {
assert(1 == scanf("%d", &A[i]));
B[i].resize(A[i]);
for (int j = 0; j < A[i]; ++j) {
assert(1 == scanf("%d", &B[i][j]));
}
}
int minimum_instructions = minimumInstructions(N, M, K, C, A, B);
printf("%d\n", minimum_instructions);
return 0;
}*/
