#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
const int NMAX = 100000;
const int lim = 18;
vector <int> G[NMAX + 5];
int t[2 * NMAX + 5] , lvl[2 * NMAX + 5] , dfn[NMAX + 5] , log2[NMAX + 5] , d[2 * NMAX + 5][lim] , n , ind;
void rmq()
{
    int i , j;
    for(i = 1 ; i <= ind ; i ++)
        d[i][0] = i;
    for(j = 1 ; (1 << j) <= ind ; j ++)
        for(i = 1 ; i + (1 << j) - 1 <= ind ; i ++)
            if(lvl[d[i][j - 1]] <= lvl[d[i + (1 << (j - 1))][j - 1]])
                d[i][j] = d[i][j - 1];
            else
                d[i][j] = d[i + (1 << (j - 1))][j - 1];
}
int query(int x , int y)
{
    int p = log2[y - x + 1];
    if(lvl[d[x][p]] <= lvl[d[y - (1 << p) + 1][p]])
        return t[d[x][p]];
    return t[d[y - (1 << p) + 1][p]];
}
void dfs(int u , int l)
{
    int v , j;
    ind ++;
    lvl[ind] = l;
    t[ind] = u;
    dfn[u] = ind;
    for(j = 0 ; j < G[u].size() ; j ++)
    {
        v = G[u][j];
        if(dfn[v] == 0)
        {
            dfs(v , l + 1);
            ind ++;
            lvl[ind] = l;
            t[ind] = u;
        }
    }
}
int main()
{
    freopen("maimute.in" , "r" , stdin);
    freopen("maimute.out" , "w" , stdout);
    int x , y , q , i , lca;
    scanf("%d" , &n);
    for(i = 1 ; i < n ; i ++)
    {
        scanf("%d%d" , &x , &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    dfs(1 , 1);
    for(i = 1 ; (1 << i) <= ind ; i ++)
        log2[(1 << i)] = 1;
    for(i = 1 ; i <= ind ; i ++)
        log2[i] = log2[i - 1] + log2[i];
    for(i = 1 ; (1 << i) <= ind ; i ++)
        log2[(1 << i)] --;
    rmq();
    scanf("%d" , &q);
    for(i = 1 ; i <= q ; i ++)
    {
        scanf("%d%d" , &x , &y);
        lca = query(min(dfn[x] , dfn[y]) , max(dfn[x] , dfn[y]));
        if(lca == x || lca == y)
            printf("DA\n");
        else
            printf("NU\n");
    }
    return 0;
}