#include <bits/stdc++.h>
using namespace std;

#define NDEBUG
#ifdef DEBUG
#include "cout11.h"
#undef NDEBUG
#endif
#include <cassert>

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> ii;
typedef pair<ll,ll> llll;
typedef pair<double,double> dd;

typedef vector<int> vi;
typedef vector<vector<int>> vvi;
typedef vector<ii> vii;
typedef vector<vector<ii>> vvii;
typedef vector<ll> vll;

#define sz(a)  int((a).size())
#define pb  push_back
#define FOR(var,from,to) for(int var=(from);var<=(to);++var)
#define rep(var,n)  for(int var=0;var<(n);++var)
#define rep1(var,n)  for(int var=1;var<=(n);++var)
#define repC2(vari,varj,n)  for(int vari=0;vari<(n)-1;++vari)for(int varj=vari+1;varj<(n);++varj)
#define ALL(c)  (c).begin(),(c).end()
#define RALL(c)  (c).rbegin(),(c).rend()
#define tr(i,c)  for(auto i=(c).begin(); i!=(c).end(); ++i)
#define found(s,e)  ((s).find(e)!=(s).end())
#define mset(arr,val)  memset(arr,val,sizeof(arr))
#define mid(x,y) ((x)+((y)-(x))/2)
#define IN(x,a,b) ((a)<=(x)&&(x)<=(b))

#define INTSPACE 12
char _buf[INTSPACE*1000000 + 3];

int loadint() {
    if (fgets(_buf, INTSPACE+3, stdin)==NULL) return 0;
    return atoi(_buf);
}
int loadvec(vector<int>& v, int N=-1) {
    if (N == -1) {
        N = loadint();
        if (N==0) return 0;
    }
    int bufsize = INTSPACE*N + 3;
    if (fgets(_buf, bufsize, stdin)==NULL) return 0;
    v.resize(N);

    int i=0;
    bool last = false;
    for (char *p=&_buf[0]; ;) {
        char *q = p;
        while (*q > ' ') ++q;
        if (*q == 0x0D || *q == 0x0A) last = true;
        *q = 0;
        v[i++] = atoi(p);
        if (last || i == N) break;
        p = q+1;
    }
    // assert(i <= N);
    return i;
}

class UnionFind {
 public:
  vector<int> data;
  UnionFind(int size) : data(size, -1) { }
  bool unionSet(int x, int y) {
    x = root(x); y = root(y);
    if (x != y) {
      if (data[y] < data[x]) swap(x, y);
      data[x] += data[y]; data[y] = x;
    }
    return x != y;
  }
  bool findSet(int x, int y) { return root(x) == root(y); }
  int root(int x) { return data[x] < 0 ? x : data[x] = root(data[x]); }
  int size(int x) { return -data[root(x)]; }
};

ll solve(int N,int M,vi& p, vvi& xy) {
    UnionFind uf(N);
    rep(i,M){
        int x = xy[i][0]-1, y = xy[i][1]-1;
        uf.unionSet(x,y);
        //printf("joint %d - %d\n", x, y);
    }
    //cerr << uf.data << endl;

    rep(i,N) --p[i];
    map<int,set<int>> ru, pu;
    set<int> rts;
    rep(i,N){
        int rt = uf.root(i);
        rts.insert(rt);
        ru[rt].insert(i);
        pu[rt].insert(p[i]);
        //printf("root %d += { %d | %d }\n", rt,i, p[i]);
    }
    int ans = 0;
    for(int rt: rts){
        //cerr << rt << " " << ru[rt] << " " << pu[rt] << endl;
        map<int,int> mp;
        for(int x:ru[rt]) ++mp[x];
        for(int x:pu[rt]) ++mp[x];
        for(auto p:mp) if(p.second==2) ++ans;
    }
    return ans;
}

int main() {
    vector<int> tmp(2);
    loadvec(tmp, 2);
    int N=tmp[0], M=tmp[1];
    vector<int> p(N);
    loadvec(p, N);
    vector<vi> xy(M, vector<int>(2));
    rep(i,M){
        loadvec(xy[i], 2);
    }
    cout << solve(N,M,p,xy) << endl;
    return 0;
}


Measured memory_bytes: 39808