program permetr;

{$APPTYPE CONSOLE}
var f:text,a,b,c,p:real;
begin
  assign(f,'input.txt');
  reset(f);
  readln (f,a,b,c);
  p:=a+b+c;
  writeln(p);
  close(f);
  assign(f,'output.txt');
  revrite(f);
  close(f);
  readln;
end.