"use strict";
const Main = (input) =>{
   let xs = input.trim().split('');
   let len = xs.length;
   let ans = 0;

    for(let i =0; i<len; i++) {
       if(xs[i]=='h' && xs[i+1]=='i' && xs[i+2]!='i') {
       	ans+=1;
       }else if(xs[i]=='i' && xs[i+1]=='i'){
        ans = 0;
       } else {
        ans+=0;
       }
    }
    if(ans>=1){
    console.log('Yes');
    }else{
    console.log('No');
    }
}
Main(require('fs').readFileSync('/dev/stdin','utf8'));