#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } else { return false; } }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } else { return false; } }
#define rep(i, s, n) for(int i = (s); i < n; i++) 
#define reps(i, s, n) for(int i = (s); i <= n; i++) 
#define rrep(i, n, s) for(int i = n; i >= (s); i--)
#define all(x) (x).begin(), (x).end()
#define print(V) for (int z = 0; z < (V).size(); z++) { cout << V[z] << " "; } cout << endl;
#define MOD 998244353
#define MOD2 1000000007
#define INF 1LL << 60
#define PI acos(-1)

int main(void) {
	string a, p, q;
	cin >> a >> p >> q;

	if (p != q) {
		cout << "Yes" << endl;
	}
	else {
		cout << "No" << endl;
	}

	return 0;
}