a.cpp

#include <bits/stdc++.h>
#define f first
#define s second
#define ll long long
#define pb push_back
#define IOS ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

using namespace std;
const int MAXN = 1e5 + 10;
const int MOD = 1e9 + 7;
vector <int> g[MAXN];
char ans[MAXN];
int cnt[MAXN];
bool removed[MAXN];
int get_cnt(int x, int pr = -1){
    cnt[x] = 1;
    for (int to : g[x]){
        if (!removed[to] && to != pr){
            cnt[x] += get_cnt(to, x);
        }
    }
    return cnt[x];
}
int get_centriod(int x, int cnt_v, int pr = -1){

    for (int to : g[x]){
        if (!removed[to] && to != pr){
            if (2 * cnt[to] > cnt_v){
                return get_centriod(to, cnt_v, x);
            }
        }
    }
    return x;
}

void run(int x, int y){
    int cnt_v = get_cnt(x, -1);
    int centroid = get_centriod(x, cnt_v, -1);

    ans[centroid] = y + 'A' - 1;
    removed[centroid] = 1;
    for (int to : g[centroid]){
        if (!removed[to]){
            run(to, y + 1);
        }
    }
}

int main(){
    IOS;
    int n;
    cin >> n;

    for (int i = 1; i < n; i++){
        int x, y;
        cin >> x >> y;
        g[x].pb(y);
        g[y].pb(x);
    }

    run(1, 1);

    for (int i = 1; i <= n; i++){
        cout << ans[i] << ' ';
    }

}