Problem:
Score : 200 points

Problem Statement

We have a long seat of width X centimeters.
There are many people who wants to sit here. A person sitting on the seat will always occupy an interval of length Y centimeters.

We would like to seat as many people as possible, but they are all very shy, and there must be a gap of length at least Z centimeters between two people, and between the end of the seat and a person.

At most how many people can sit on the seat?

Constraints

All input values are integers.

1 \leq X, Y, Z \leq 10^5

Y+2Z \leq X

Input

Input is given from Standard Input in the following format:

X Y Z

Output

Print the answer.

Sample Input 1

13 3 1

Sample Output 1

3

There is just enough room for three, as shown below:

Figure

Sample Input 2

12 3 1

Sample Output 2

2

Sample Input 3

100000 1 1

Sample Output 3

49999

Sample Input 4

64146 123 456

Sample Output 4

110

Sample Input 5

64145 123 456

Sample Output 5

109

Solution in Pascal (FPC 2.6.2) (judge verdict: Accepted)

program Project1;
             
{$APPTYPE CONSOLE}
         
uses
  SysUtils,math;
var
  g,l,r,a,h,w,i,j,count,x,y,sw,m,n,b,c,soeji,sum,max,k,t,z:Integer;
  //l:array of Integer;
  s,s123,s1,s2,s3:string;
  tf:Boolean;
  //nyu:TStringList;
  xc,yc,space:char;
begin
  try
    { TODO -oUser -cConsole Main : ここにコードを記述してください }
    Read(x);
    Read(y);
    Readln(z);
    Writeln((x-z) div (y+z));
    Readln;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
end.