#include <bits/stdc++.h>

#define rep(i, a, b) for(int i = (a); i <= (b); i++)
#define pre(i, a, b) for(int i = (a); i >= (b); i--)
#define Ede(i, u) for(int i = h[u]; i; i = ne[i])
#define go(i, a) for(auto i : a)
//#define int long long
#define LL long long
#define ULL unsigned long long
#define PII pair<int, int>
#define PIL pair<int, long long>
#define PLI pair<long long, int>
#define PLL pair<long long, long long>
#define mp make_pair
#define eb emplace_back
#define opb pop_back
#define pb push_back
#define pf push_front
#define fi first
#define se second
#define sf scanf
#define prf printf
#define el putchar('\n')
#define mms(arr, n) memset(arr, n, sizeof(arr))
#define mmc(arr1, arr2) memcpy(arr1, arr2, sizeof(arr2))
const int inf = 0x3f3f3f3f;

template <typename T> inline void rd(T &x){
	x = 0; bool f = true; char ch = getchar();
	while(ch < '0' || ch > '9'){ if(ch == '-') f = false; ch = getchar();}
	while(ch >= '0' && ch <= '9'){ x = (x << 1) + (x << 3) + (ch ^ '0'); ch = getchar();}
	if(!f) x = -x;
}
template <typename T, typename ...Args> inline void rd(T &x, Args &...args){ rd(x); rd(args...);}

using namespace std;

const int N = 100010, M = N << 1;
int h[N], e[N], ne[N], idx;
void add(int a, int b){
	e[++idx] = b, ne[idx] = h[a], h[a] = idx++;
}
int n, m;
int siz;
int a[N];
int ds[M], cnt; //dfs序
int s[N], t[N]; //节点起始点,结尾点在ds序中的编号 
int fa[N][20], dep[N];
int ans[M], res;
//LCA 
void dfs(int u){
	dep[u] = dep[fa[u][0]] + 1;
	ds[++cnt] = u, s[u] = cnt;
	for(int i = 1; i < 20; i++) fa[u][i] = fa[fa[u][i - 1]][i - 1];
	Ede(i, u){
		int v = e[i];
		if(v != fa[u][0]) fa[v][0] = u, dfs(v);
	}
	ds[++cnt] = u, t[u] = cnt; 
}
int LCA(int x, int y){
	if(dep[x] < dep[y]) swap(x, y);
	for(int i = 19; i >= 0; i--){
		if(dep[fa[x][i]] >= dep[y]) x = fa[x][i];
	}
	if(x == y) return x;
	for(int i = 19; i >= 0; i++){
		if(fa[x][i] != fa[y][i]) x = fa[x][i], y = fa[y][i];
	}
	return fa[x][0];
}

struct Qu{
	int l, r;
	int id, x;
}qu[N];
bool cmp(Qu a, Qu b){
	if(a.l / siz != b.l / siz) return a.l < b.l;
	else return a.r < b.r;
}

int vis[N]; //标记一个节点是否存在 
int ccnt[N];
void modify(int x){
	if(!vis[x]){
		vis[x]++;
		ccnt[a[x]]++;
		if(ccnt[a[x]] == 1) res++;
	}else{
		vis[x]--;
		ccnt[a[x]]--;
		if(!ccnt[a[x]]) res--;
	}
} 

int main(){
	/*
	freopen(".in", "r", stdin);
	freopen(".out", "w", stdout);
	*/
	rd(n, m);
	siz = sqrt(m); //?
	rep(i, 1, n) rd(a[i]);
	for(int i = 1, x, y; i <= m; i++){
		rd(x, y);
		add(x, y), add(y, x);
	}
	dfs(1);
	for(int i = 1, u, v, lca; i <= m; i++){
		rd(u, v); lca = LCA(u, v);
		if(u == lca || v == lca){
			if(s[u] > s[v]) swap(u, v);
			qu[i].l = s[u], qu[i].r = s[v];
		}else{
			if(s[v] > t[u]) swap(u, v);
			qu[i].l = t[u], qu[i].r = s[v];
			qu[i].x = lca;
		}
	}
	sort(qu + 1, qu + m + 1, cmp);
	for(int i = 1, l = qu[1].l, r = qu[1].l - 1; i <= m; i++){
		while(l < qu[i].l) modify(ds[l++]);
		while(r > qu[i].r) modify(ds[r--]);
		while(l > qu[i].l) modify(ds[--l]);
		while(r < qu[i].r) modify(ds[++r]);
		if(qu[i].x) modify(qu[i].x);
		//判断是否记录了lca,若记录了则x,y都不是lca,需要加入序列中 
		ans[qu[i].id] = res;
		if(qu[i].x) modify(qu[i].x);
	}
	rep(i, 1, m) prf("%d\n", ans[i]);
	return 0;
}