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#include <fstream>
#include <vector>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int rmq[20][200005],nr,i,x,n,m,p[100005],l[200005],d,y,j,q;
vector <int> G[100005];
void dfs(int x)
{
rmq[0][++nr]=x;
if(!p[x])
p[x]=nr;
for(int i=0;i<G[x].size();i++)
{
dfs(G[x][i]);
rmq[0][++nr]=x;
}
}
int main()
{
f>>n>>m;
for(i=2;i<=n;i++)
{
f>>x;
G[x].push_back(i);
}
dfs(1);
l[1]=0;
for(i=2;i<=nr;i++)
l[i]=l[i/2]+1;
for(i=1;(1<<i)<=nr;i++)
for(j=1;j<=nr;j++)
rmq[i][j]=min(rmq[i-1][j],rmq[i-1][j+(1<<(i-1))]);
for(i=1;i<=m;i++)
{
f>>x>>y;
if(p[x]>p[y])
swap(x,y);
d=l[p[y]-p[x]];
g<<min(rmq[d][p[x]],rmq[d][p[y]-(1<<d)+1])<<'\n';
}
return 0;
}