Const
 N=20;

Type
 Arr=Array[1..20] of Integer;

Var
 A:Arr;
 i:Integer;
 b:boolean;

Procedure Test_equal(T:Arr; var TB:boolean);
var
 p,q:Integer;
 bb:boolean;
begin
 bb:=false;
 p:=0;
 Repeat
  p:=p+1;
  for q:=p+1 to N do
   if A[p]=A[q] then bb:=true;
 Until bb or (p=N-1);
 TB:=bb;
end;

Begin
 For i:=1 to N do
  begin
   write('A[',i:2,']= ');
   readln(A[i]);
  end;
 writeln;
 For i:=1 to N do Write(A[i]:8);
 Test_equal(A,b);
 If b then writeln('Yes!') else writeln('No!');
 Readln
End.