function Main(input) {
  input = input.replace(/\n/g, ' ');
  input = input.split("");
  var ans = "Yes";
  for(var i=0;i<input.length;i++){
    if(!(input[i]=="h" && input[++i]=="i")){
      ans="No";
      break;
    }
  }
  console.log(ans);

}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));