#include<stdio.h>
#include<vector>

#define maxn 100005

using namespace std;

FILE*f=fopen("lca.in","r");
FILE*g=fopen("lca.out","w");

int n,q;
int lant[maxn],height[maxn],tata_lant[maxn],niv[maxn];
vector<int>G[maxn];

void dfs ( int nod ){
	
	for ( vector<int>::iterator itt = G[nod].begin() ; itt != G[nod].end() ; ++itt ){
		int fiu = (*itt);
		
		niv[fiu] = niv[nod]+1;
		dfs(fiu);
		tata_lant[ lant[fiu] ] = nod;
		if ( height[ lant[fiu] ] > height[ lant[nod] ] ){
			lant[nod] = lant[fiu];
		}
	}
	
	if ( !lant[nod] ){
		lant[nod] = ++lant[0];
	}
	++height[lant[nod]];
}

inline int lca ( int x , int y ){
	
	while ( lant[x] != lant[y] ){
		
		if ( niv[ tata_lant[lant[x]] ] >= niv[ tata_lant[lant[y]] ] ){
			x = tata_lant[lant[x]];
		}
		else{
			y = tata_lant[lant[y]];
		}
	}
	
	if ( niv[x] < niv[y] ){
		return x;
	}
	else{
		return y;
	}
}

int main () {
	
	fscanf(f,"%d %d",&n,&q);
	int t;
	for ( int i = 2 ; i <= n ; ++i ){
		fscanf(f,"%d",&t);
		G[t].push_back(i);
	}
	
	dfs(1);
	
	tata_lant[ lant[1] ] = 0; niv[0] = -1;
	int x,y;
	for ( int i = 1 ; i <= q ; ++i ){
		fscanf(f,"%d %d",&x,&y);
		fprintf(g,"%d\n",lca(x,y));
	}
	
	fclose(f);
	fclose(g);
	
	return 0;
}