program paradox; 
var n, i, R, count:integer;
    S: array[1..325] of string;
    A,B,SY: array [1..325] of char;
    lettere : array[1..26] of integer;
    risposta: string;
begin
    readln(N);
    for i:=1 to  N  do readln(S[i]);
    for i:=1 to N do begin A[i]:=S[i][1]; SY[i]:=S[i][3]; B[i]:=S[i][5];end;
    for i:=1 to 26 do lettere[i]:=0;
    for i:=1 to N do begin if SY[i]='<' then lettere[ord(A[i])-96]:=lettere[ord(A[i])-96]+1
                                        else lettere[ord(B[i])-96]:=lettere[ord(B[i])-96]+1; end;
    risposta:=':('; count:=0;
    for i:=1 to 26 do begin if lettere[i]=0 then count:=count+1; end;
    if 26-count=N then risposta:=':('
                 else begin  for i:=1 to 26 do if ((lettere[i]=2) or (lettere[i]=1))  then R:=R+1; if R=N-1 then risposta:=':)';end; 
    writeln(risposta);
end.

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

MwphICZndDsgYgpjICZsdDsgYgphICZsdDsgYw==

3
a > b
c < b
a < c