function Main(input) {
	input = input.split("");
	var flag = true;
	if(input.length%2==1) flag = false;
	for(var i=0;i<input.length/2;i++){
		if(input[i*2]=="h"&&input[i*2+1]=="i"){
			
		}else{
			flag = false;
		}
		if(!flag){
			break;
		}
	}
if(flag){
	console.log("Yes")
}else{
	console.log("No")
}
}Main(require("fs").readFileSync("/dev/stdin", "utf8").trim());