#include<iostream>
#include <list>
#include<vector>
#include<queue>
using namespace std;

void BFS(int s,int* parent,bool* visited,int N,vector<vector<int> >& pairs,int* depth)
{
    visited[s] = true;
    depth[s] = 0;
    queue<int> q;q.push(s);
    while(!q.empty())
    {
        int s = q.front();
        q.pop();
        vector<int>::iterator i;
        for(i=pairs[s].begin();i!=pairs[s].end();i++)
        {
            if(!visited[*i])
            {
                visited[*i] = true;
                q.push(*i);
                parent[*i] = s;
                depth[*i] = depth[s]+1;
            }
        }
    }
}
int findLCA(int u,int v,int* parent)
{
    if(u==v)    return u;
    else return findLCA(parent[u],parent[v],parent);
}
int gcd(int a,int b){
    return (b==0) ? a : gcd(b, a%b);
  }
int countPairs(queue<int>& q,int* nodeV)
{
    vector<int> arr;
    int k=0;
    while(!q.empty())
    {
        arr.push_back(nodeV[q.front()]);
        q.pop();
        k++;
    }int count = 0;
    for(int i=0;i<k-1;i++)
    {
        for(int j=i+1;j<k;j++)
        {
            if(gcd(arr[i],arr[j]) == 1) count++;
        }
    }
    return count;
}
int main(){
    int N,q;cin>>N>>q;
    int* nodeV = new int[N];
    for(int i=0;i<N;i++)    cin>>nodeV[i];
    vector<vector<int> >pairs(N);
    for(int i=0;i<N-1;i++)
    {
        int u,v;cin>>u>>v;
        pairs[u-1].push_back(v-1);
        pairs[v-1].push_back(u-1);
    }
    int* parent = new int[N];
    int* depth = new int[N];
    bool* visited = new bool[N];
    for(int i=0;i<N;i++)
    {
        parent[i] = -1;depth[i] = -1;
        visited[i] = false;
    }
    int s=0;
    BFS(s,parent,visited,N,pairs,depth);
    //for(int i=0;i<N;i++)    cout<<parent[i]<<" ";
    for(int i=0;i<q;i++)
    {
        int u,v;cin>>u>>v;u=u-1;v=v-1;
        int k1 = depth[u];
        int k2 = depth[v];
        queue<int> q;
        while(k1!=k2)
        {
            if(k1>k2)
            {
                q.push(u);
                u = parent[u];k1--;
            }
            else
            {
                q.push(v);
                v = parent[v];k2--;
            }
        }
        if(u==v && q.empty()==true)
        {
            cout<<"0\n";
        }
        else
        {
            int lca = findLCA(u,v,parent);
            while(u!=lca)
            {
                q.push(u);
                u = parent[u];
        }
        while(v!=lca)
        {
            q.push(v);
            v = parent[v];
        }
        q.push(lca);
        int total = countPairs(q,nodeV);
        cout<<total<<"\n";
        }
    }
    return 0;
}