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//Lowest Common Ancestor
//Complexitate : Memorie O(n*(log2(n))) , Timp O((n*log2(n)+m*log2(n)));
#include <cstdio>
#include <vector>
#include <fstream>
#define nmax 100005
#define kmax 18
using namespace std;
int n,m,lev[nmax];
int t[nmax][kmax];
vector <int> v[nmax];
class instream {
public:
instream() {}
instream(const char *file_name) {
input_file=fopen(file_name,"r");
cursor=0;
fread(buffer,SIZE,1,input_file);
}
inline instream &operator >>(int &n) {
while((buffer[cursor]<'0'||buffer[cursor]>'9')&&buffer[cursor]!='-') {
advance();
}
n=0;
while('0'<=buffer[cursor]&&buffer[cursor]<='9') {
n=n*10+buffer[cursor]-'0';
advance();
}
return *this;
}
private:
FILE *input_file;
static const int SIZE=1<<18;
int cursor;
char buffer[SIZE];
inline void advance() {
++ cursor;
if(cursor==SIZE) {
cursor=0;
fread(buffer,SIZE,1,input_file);
}
}
};
instream f("lca.in");
ofstream fout("lca.out");
void dfs(int x)
{
int i;
for (i=0;i<v[x].size();i++) {
lev[v[x][i]]=lev[x]+1;
dfs(v[x][i]);
}
}
int main()
{
int i,j,k,a,b;
int x,y;
f>>n>>m;
for (i=2;i<=n;i++) {
f>>j;
t[i][0]=j;
v[j].push_back(i);
}
for (k=1;(1<<k)<=n;k++)
for (i=1;i<=n;i++)
t[i][k]=t[t[i][k-1]][k-1];
dfs(1);
for (i=1;i<=m;i++) {
f>>a>>b;
if (lev[a]>lev[b])
swap(a,b);
for (k=0;(1<<k)<lev[b];k++);
for (;k>=0;k--)
if (lev[b]-(1<<k)>=lev[a])
b=t[b][k];
if (a==b) {
fout<<a<<'\n';
continue;
}
for (k=0;(1<<k)<lev[b];k++);
for (;k>=0;k--)
if (t[a][k]&&t[b][k]&&t[a][k]!=t[b][k]) {
a=t[a][k];
b=t[b][k];
}
fout<<t[a][0]<<'\n';
}
return 0;
}