program fail;
var F:text; x,y:integer; s:string; c:boolean;
begin
Assign(F,'D:\pr1.txt');
reset(F);
read(F);
x:=0;
while pos(' ',s)<>0 do begin
c:=((s[1])=pos(' ',s) and (s[2])<>pos(' ',s));
if c:=true
 then x:=x+1;
 delete (s,1,1);
 else delete (s,1,1);
 end;
end;
  WriteLn(x);
  Readln;
  readln;
end.