//subtask K <= 1000
#include "island.h"
#include<bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 5;
const int maxk = 1000 + 5;
const int inf = 1e8;
int n, m, k;
int a[maxn];
vector<int> have[maxk];
int head[maxn];
vector<pair<int,int>> way[maxn];
int dis[maxn];
int ans[maxk][maxk];
int q[maxn*5];
int findhead(int x) {
if(head[x]==x) return x;
return head[x] = findhead(head[x]);
}
void bfs(int ban) {
int l = 1, r = 0;
for(int u=0;u<n;u++) {
dis[u] = 0;
if(a[u] == ban) {
dis[u] = m;
q[++r] = u;
}
}
while(l<=r) {
int u = q[l++];
ans[ban][a[u]] = max(ans[ban][a[u]], dis[u]);
for(auto tmp : way[u]) {
int v = tmp.first, val = tmp.second;
if(dis[v] >= min(dis[u], val) || a[v] == ban) continue;
dis[v] = min(dis[u], val);
q[++r] = v;
}
}
}
void Init(int K, vector<int> F, vector<int> S, vector<int> E){
n = F.size(); m = S.size(); k = K;
for(int i=0;i<n;i++) {
a[i] = F[i];
have[a[i]].push_back(i);
}
for(int i=0;i<n;i++) head[i] = i;
for(int i=m-1;i>=0;i--) {
if(findhead(S[i])!=findhead(E[i])) {
head[findhead(S[i])] = findhead(E[i]);
way[S[i]].push_back({E[i], i});
way[E[i]].push_back({S[i], i});
//printf("edge %d %d\n",S[i],E[i]);
}
}
for(int x=0;x<k;x++) {
//if((int)have[x].size() >= wow) {
bfs(x);
//}
}
}
int Separate(int A, int B){
return ans[A][B] + 1;
//if((int)have[A].size() >= wow) return ans[A][B] + 1;
//if((int)have[B].size() >= wow) return ans[B][A] + 1;
}
/*
#include <stdio.h>
#include <stdlib.h>
static void my_assert(int TF, const char* message){
if(!TF){ puts(message); exit(0); }
}
int main(){
int N, M, K, Q;
std::vector<int> F, S, E;
my_assert(scanf("%d%d%d%d", &N, &M, &K, &Q) == 4, "Error: Invalid Input");
my_assert(1 <= K && K <= N && N <= 300000, "Error: Invalid Input");
my_assert(N - 1 <= M && M <= 1000000, "Error: Invalid Input");
my_assert(1 <= Q && Q <= 300000, "Error: Invalid Input");
for(int i = 0; i < N; i++){
int a;
my_assert(scanf("%d", &a) == 1, "Error: Invalid Input");
my_assert(0 <= a && a < K, "Error: Invalid Input");
F.push_back(a);
}
for(int i = 0; i < M; i++){
int a, b;
my_assert(scanf("%d%d", &a, &b) == 2, "Error: Invalid Input");
my_assert(0 <= a && a < N && 0 <= b && b < N && a != b, "Error: Invalid Input");
S.push_back(a), E.push_back(b);
}
Init(K, F, S, E);
for(int i = 0; i < Q; i++){
int a, b;
my_assert(scanf("%d%d", &a, &b) == 2, "Error: Invalid Input");
my_assert(0 <= a && a < K && 0 <= b && b < K && a != b, "Error: Invalid Input");
printf("%d\n", Separate(a, b));
}
return 0;
}
*/
