program Project2;

{$APPTYPE CONSOLE}

var a,b,c,d :integer;
    f,t :text;
begin
  assign(f,'storonu.dat');
  reset(f);
  readln(f,a);
  readln(f,b);
  readln(f,c);
  close(f);
  assign(t,'perumetr.sol');
  rewrite(t);
  if (a+b>c) or (a+c>b) or (c+b>a) then write(t,'trukytnuka ne isnue') else d:=a+b+c;
  write(t,d:3);
  close(t);
end.