#include <bits/stdc++.h>

using namespace std;
const int c=200005;
int n, si[c], si2[c], cent, baj;
vector<int> sz[c];
bool v[c], v2[c];
void dfs(int a) {
    v[a]=true;
    si[a]=1;
    for (auto x:sz[a]) {
        if (!v[x]) {
            dfs(x);
            si[a]+=si[x];
        }
    }
    if (!cent && 2*si[a]>=n) {
        cent=a;
    }
}
void dfs2(int a) {
    si[a]=1;
    v2[a]=true;
    vector<int> sor;
    for (auto x:sz[a]) {
        if (!v2[x]) {
            dfs2(x);
            sor.push_back(si[x]);
        }
    }
    sort(sor.begin(), sor.end());
    for (auto x:sor) {
        if (x>si[a]) {
            baj=1;
        }
        si[a]+=x;
    }
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin >> n;
    for (int i=1; i<n; i++) {
        int a, b;
        cin >> a >> b;
        sz[a].push_back(b), sz[b].push_back(a);
    }
    dfs(1);
    dfs2(cent);

    cout << (baj ? "NO" : "YES") << "\n";
    return 0;
}
/*
6
4 5
5 6
6 1
2 6
3 2

*/