#include using namespace std; int main() { int i; int X; int Y; int N; int A; int iPre; int iNow; cin >> X; cin >> Y; cin >> N; iPre = 0; for( i = 0; i < N; i++ ) { cin >> A; iNow = iPre + A; if( iPre * Y > iNow * X ) { cout << "NO" << endl; return 0; } iPre = iNow; } cout << "YES" << endl; return 0; }