"use strict";
const Main = (input) =>{
   let xs = input.trim().split(' ').map(v=>parseInt(v,10));
   let i = xs[1]+1
   let max = i + xs[1]
   let ans = 0;
   if(xs[0] <= xs[1]){
    ans = 1;
   }else{
     ans = Math.ceil(xs[0] / max);
   } 
   console.log(ans);   
}
Main(require('fs').readFileSync('/dev/stdin','utf8'));