#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
template<typename T>inline bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
    string a, p, q;
    cin >> a >> p >> q;
    if(p!=q){
      cout << "Yes" << endl;
    }
    else{
      cout << "No" << endl;
    }
    return 0;
}