#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1 &x, T2 y) { return y < x ? (x = y, true) : false; }
template<typename T1, typename T2> bool chkmax(T1 &x, T2 y) { return y > x ? (x = y, true) : false; }
void debug_out() { cerr << endl; }
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) { cerr << ' ' << A; debug_out(B...); }
template<typename T> void mdebug_out(T* a, int n) { for (int i = 0; i < n; ++i) cerr << a[i] << ' '; cerr << endl; }
#ifdef DEBUG
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
#define debug(...) 1337
#define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T> &v) { for (auto x : v) stream << x << ' '; return stream; }
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) { return stream << p.first << ' ' << p.second; }
int findSwapPairs(int n, int* s, int m, int* X, int* Y, int* ansX, int* ansY) {
auto good = [&](int k, bool restore) {
vector<int> p(s, s + n);
for (int i = 0; i < k; ++i) {
swap(p[X[i]], p[Y[i]]);
}
vector<char> used(n, false);
int ptr = 0;
vector<int> u(k), v(k);
for (int x = 0; x < n; ++x) {
if (!used[x]) {
int y = x;
do {
used[y] = true;
if (p[y] != x) {
if (ptr == k) {
return false;
}
u[ptr] = y;
v[ptr] = p[y];
++ptr;
}
y = p[y];
} while (y != x);
}
}
if (restore) {
vector<int> p(s, s + n);
vector<int> ip(n);
for (int x = 0; x < n; ++x) {
ip[p[x]] = x;
}
for (int i = 0; i < k; ++i) {
int a = p[X[i]];
int b = p[Y[i]];
swap(p[X[i]], p[Y[i]]);
swap(ip[a], ip[b]);
int k = ip[u[i]];
int l = ip[v[i]];
ansX[i] = k;
ansY[i] = l;
swap(p[k], p[l]);
swap(ip[u[i]], ip[v[i]]);
}
}
return true;
};
int vl = -1;
int vr = m;
while (vr - vl > 1) {
int vm = (vl + vr) >> 1;
if (good(vm, false)) {
vr = vm;
} else {
vl = vm;
}
}
good(vr, true);
return vr;
}
#ifdef DEBUG
signed main() {
#ifdef DEBUG
freopen("in", "r", stdin);
#endif
ios::sync_with_stdio(0);
cin.tie(0);
int n;
cin >> n;
int* s = new int[n];
for (int x = 0; x < n; ++x) {
cin >> s[x];
}
int m;
cin >> m;
int* x = new int[m];
int* y = new int[m];
for (int i = 0; i < m; ++i) {
cin >> x[i] >> y[i];
}
int* p = new int[m];
int* q = new int[m];
int R = findSwapPairs(n, s, m, x, y, p, q);
cout << R << '\n';
for (int i = 0; i < R; ++i) {
cout << p[i] << ' ' << q[i] << '\n';
}
return 0;
}
#endif
