#include<bits/stdc++.h>
#define print(x) cout << (#x) << ": " << (x) << endl
#define p1d(x) cout << (#x) << ": ["; for(auto& zz: x) cout << zz << " "; cout << "]\n"
#define p2d(x) cout << (#x) << ": \n["; for(auto& vec: x) {for(auto& v: vec) cout << v << " "; cout << ",\n";}
#define p2s(x) cout << (#x) << ": ["; for(auto& vec: x) {cout << vec << ",\n";}
#define pb push_back
#define endl "\n"
// __builtin_popcount

typedef long long ll;
using namespace std;
int static fast = [](){
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0); return 0;
}();
// freopen("input.txt", "r", stdin);
int main() {
    int n, val;
    cin >> n;
    vector<int> rec(n+1, 0);
    for(int i = 0; i < n; i++) {
        cin >> val;
        rec[val] = 1;
    }
    for(int i = 1; i <= n; i++) {
        if (rec[i] == 0) {
            cout << "No" << endl;
            return 0;
        }
    }
    cout << "Yes" << endl;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
#define fastio   ios_base::sync_with_stdio(false), cin.tie(0), cout.tie(0)
#define endl "\n"

int main()
{
    fastio;

    int n,a;
    cin>> n;

    vector <int> v;
    list <int> lst;

    while(n!=0)
    {
        cin>> a;
        v.push_back(a);
        lst.push_back(a);
        n--;
    }

    lst.sort();
    lst.unique();

    if(lst.size()==v.size())
        cout<< "Yes";
    else
        cout<< "No";

    return 0;
}
