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

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NQphICZndDsgZgpiICZndDsgYwphICZsdDsgZApkICZsdDsgYwpmICZsdDsgYg==

5
a > f
b > c
a < d
d < c
f < b