#include <iostream> using namespace std; int main() { int c=0; double last,next; bool sort=true; cin >> next; while(next) { last = next; cin >> next; if(next >= last) sort = false; c++; } if(c<2) cout << "Error!" << endl; else if(sort) cout << "Yes" << endl; else cout << "No" << endl; cin.get(); cin.get(); }