#include<bits/stdc++.h>
#define pb emplace_back
#define AI(i) begin(i), end(i)
using namespace std;
using ll = long long;
//#undef KEV
#ifdef KEV
#define DE(args...) kout("[ " + string(#args) + " ] = ", args)
void kout() {cerr << endl;}
template<class T1, class ...T2>
void kout (T1 v, T2 ...e) { cerr << v << ' ', kout(e...); }
template<class T>
void debug(T L, T R) { while (L != R) cerr << *L << " \n"[next(L)==R], ++L; }
#else
#define DE(...) 0
#define debug(...) 0
#endif
const int MAX_N = 300010;
int n;
vector<pair<int,int>> op;
// just the front half
void swap_sort(vector<int> p) {
vector<int> pos(n+1);
int m = n/2;
for (int i = 0; i < n;++i)
pos[ p[i] ] = i;
auto sw = [&](int x, int y) {
op.pb(x, y);
swap(p[x], p[y]), swap(pos[p[x]], pos[p[y]]);
};
for (int i = 0;i < m;++i) {
while (i+1 != p[i])
sw(i, pos[i+1]);
}
}
bool valid(vector<int> p) {
int cnt = 0, m = n / 2;
for (int l = 0, r = n-1;l < r;++l, --r) {
if ((p[l]>m) ^ (p[r]<=m))
return false;
if (p[l] > m)
++cnt;
}
if (cnt & 1)
return false;
DE(cnt);
vector<int> ln, rn;
for (int i = 0;i < m;++i)
if (p[i] > m)
ln.pb(i);
for (int i = n-1;i >= m;--i)
if (p[i] <= m)
rn.pb(i);
assert(cnt == ln.size() && cnt == rn.size());
vector<int> pos(n+1);
for (int i = 0;i < n;++i)
pos[ p[i] ] = i;
auto sw = [&](int x, int y) {
swap(p[x], p[y]), swap(pos[ p[x] ], pos[ p[y] ]);
};
auto do_op = [&](int x, int y) {
int a = x, b = y, c = n - x - 1, d = n - y - 1;
sw(a, b), sw(c, d);
};
for (int i = 0;i < cnt;i += 2)
do_op(ln[i], rn[i+1]);
for (int i = 0;i < m;++i) {
while (i+1 != p[i]) {
do_op(i, pos[i+1]);
}
}
for (int i = 0;i < n;++i)
if (p[i] != i+1)
return false;
return true;
}
// make p good enough so that I can do swap sort on it
vector<int> pair_good(vector<int> p) {
vector<int> notp;
vector<int> pos(n+1);
vector<int> goodp(p);
debug(AI(p));
auto put = [&](int id) {
DE(id);
notp.pb(id);
};
auto sw = [&](int a, int b) {
swap(p[a], p[b]), swap(pos[ p[a] ], pos[ p[b] ]);
};
auto do_op = [&](int x, int y) {
DE(x, y);
int a = x, b = y, c = n - a - 1, d = n - b - 1;
swap( goodp[a], goodp[b] );
swap( goodp[c], goodp[d] );
op.pb(a, b);
};
auto pop = [&]() {
while (notp.size() > 1) {
int a = notp.back(); notp.pop_back();
int b = notp.back(); notp.pop_back();
do_op(a, n-b-1);
}
};
int m = n / 2;
vector<bool> ch(n), vis(n);
int cnt = 0;
for (int i = 0;i < m;++i)
if (p[i] > m)
swap(p[i], p[n-i-1]), ch[i] = true, ++cnt;
for (int i = 0;i < m;++i)
pos[p[i]] = i;
DE(cnt);
debug(AI(p));
for (int i = 0;i < m;++i) {
if (vis[i]) continue;
vis[i] = true;
if (ch[i])
put(i);
while (i+1 != p[i]) {
int x = p[i]-1;
if (ch[x])
put(x);
vis[x] = true;
sw(i, x);
}
pop();
}
assert(notp.empty());
cerr << "GoodP\n";
debug(AI(goodp));
return goodp;
}
bool solve() {
cin >> n;
vector<int> p(n);
for (int &i : p)
cin >> i;
debug(AI(p));
if (!valid(p))
return false;
p = pair_good(p);
swap_sort(p);
return true;
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0);
int T;
cin >> T;
while (T--) {
op.clear();
if (!solve()) {
cout << -1 << '\n';
}
else {
cout << op.size() << ' ' << op.size() << '\n';
for (auto [a, b] : op)
cout << a+1 << ' ' << b+1 << '\n';
}
}
}
