# include <cstdio>
# include <vector>
# include <algorithm>

using namespace std;

# define FIN "lca.in"
# define FOUT "lca.out"

const int T = 1;
const int LOG_2N = 19;
const int MAX_N = 100005;

# define inf 0x3f3f3f3f

int N, M, i, j, cnt;
int Poz[MAX_N];
int depth[MAX_N];
int LOG[MAX_N << 1];
vector <int> G[MAX_N];
int RMQ[LOG_2N][MAX_N << 1];

    void df(int Nod, int Level) {
        depth[Nod] = Level;
        RMQ[0][Poz[Nod] = ++cnt] = Nod;
        
        vector <int> :: iterator it;
        for (it = G[Nod].begin(); it != G[Nod].end(); ++it) {
           df(*it, Level + 1);
           RMQ[0][++cnt] = Nod;
        }
    }

    int main() {
        freopen(FIN, "r", stdin);
        freopen(FOUT, "w", stdout);
        
        scanf("%d%d", &N, &M);
        
        int temp;
        for (i = 2; i <= N; ++i) {
            scanf("%d", &temp);
            G[temp].push_back(i);
        }
        
        df(T, 0);
        
        LOG[1] = 0;
        for (i = 2; i <= cnt; ++i)
           LOG[i] = LOG[i >> 1] + 1;
        
        depth[0] = inf;
        for (i = 1; i <= LOG[cnt]; ++i)
           for (j = 1; j + (1 << i) - 1 <= cnt; ++j)
               RMQ[i][j] = depth[RMQ[i - 1][j]] < depth[RMQ[i - 1][j + (1 << (i - 1))]] ?
               RMQ[i - 1][j] : RMQ[i - 1][j + (1 << (i - 1))];
        
        int a, b, pw;
        for (i = 1; i <= M; ++i) {
            scanf("%d%d", &a, &b);
            
            if (Poz[a] > Poz[b]) { temp = a; a = b; b = temp; }
            
            pw = LOG[Poz[b] - Poz[a]];
            printf("%d\n", depth[RMQ[pw][Poz[a]]] < depth[RMQ[pw][Poz[b] - (1 << pw) + 1]] ? 
                           RMQ[pw][Poz[a]] : RMQ[pw][Poz[b] - (1 << pw) + 1]);
        }
        
        return 0;
    }