#include <vector>
#include <algorithm>
#include <iostream>
#include <cstdio>
#include <climits>
using namespace std;

typedef vector<int> VI;
typedef vector <VI> VVI;
#define PB push_back
#define FOR(i,a,b) for(int i=(a); i<=(b); ++i)
#define REP(i,n) for(int i=0; i<(n); ++i)
#define ALL(X) (X).begin(),(X).end()
#define FORE(it,X) for(__typeof((X).begin()) it=(X).begin(); it!=(X).end();++it)

int N, Q;
VI A; //parent
VI D; //depth
VVI B; //childs
VI locInTrip, no2serial, serial2no;
int nextSerial;

struct RMQ {
  int n;
  VI rangeMin;
  RMQ(const VI &array) {
    n = array.size();
    int m = 1; while(m < n) m <<= 1;
    rangeMin.resize(m * 2);
    init(array, 0, n-1, 1);
  }
  int init(const VI &array, int l, int r, int node) {
    if(l == r) return rangeMin[node] = array[l];
    int mid = (l+r)/2;
    int lMin = init(array, l, mid, node * 2);
    int rMin = init(array, mid + 1, r, node * 2 + 1);
    return rangeMin[node] = min(lMin, rMin);
  }
  int query(int l, int r, int node, int nodeL, int nodeR) {
    if(r < nodeL or nodeR < l) return INT_MAX;
    if(l <= nodeL and nodeR <= r) return rangeMin[node];
    int mid = (nodeL + nodeR) / 2;
    return min(query(l, r, node*2, nodeL, mid), query(l, r, node*2+1, mid+1, nodeR));
  }
  //[l,r)
  int query(int l, int r) {
    return query(l, r, 1, 0, n-1);
  }
  int update(int idx, int newVal, int node, int nodeL, int nodeR) {
    if(idx < nodeL or nodeR < idx)
      return rangeMin[node];
    if(nodeL == nodeR) return rangeMin[node] = newVal;
    int mid = (nodeL + nodeR) / 2;
    return rangeMin[node] = min(
        update(idx, newVal, node * 2, nodeL, mid),
        update(idx, newVal, node * 2 + 1, mid + 1, nodeR));
  }
  int update(int idx, int newVal) {
    return update(idx, newVal, 1, 0, n-1);
  }
};

void preorder(int cur, int depth, VI &ret) {
  no2serial[cur] = nextSerial;
  serial2no[nextSerial] = cur;
  ++nextSerial;
  D[cur] = depth;
  locInTrip[cur] = ret.size();
  ret.PB(no2serial[cur]);
  FORE(i, B[cur]) {
    preorder(*i, depth+1, ret);
    ret.PB(no2serial[cur]);
  }
}
int solve() {
  cin >> N >> Q;
  A = VI(N); A[0] = -1; REP(i, N-1) scanf("%d", &A[i+1]);
  B = VVI(N, VI()); REP(i, N-1) B[A[i+1]].PB(i+1);
  D = VI(N); 
  VI ret;
  locInTrip = VI(N);
  serial2no = VI(N); no2serial = VI(N);
  nextSerial = 0;
  preorder(0, 0, ret);
  /*REP(i, N) P(i,B[i]);
  P(ret)*/

  RMQ R(ret); 
  REP(i, Q) {
    int a, b;
    cin >> a >> b;
    int ans = D[a] + D[b];
    int u = locInTrip[a], v = locInTrip[b];
    if(u > v) swap(u, v);
    int lca = serial2no[R.query(u, v)];
    ans -= 2*D[lca];
    printf("%d\n", ans);
  }
  return 0;
}

int main() {
  int T; cin >> T; REP(i, T)
    solve();
  return 0;
}