Const size = 4;

Var arr:                array [1..size] of Integer;
    i:                  Integer;

Begin
    if(Boolean(size xor 4)) then
    Begin
        WriteLn('Iou are f*cking st*pid b*tch');
        exit;
    End
    else
    Begin
        for i := 1 to size do
            Read(arr[i]);
        if(arr[1] <> arr[2]) then
        Begin
            if(arr[2] <> arr[3]) then
                WriteLn('[2]')
            else
                WriteLn('[1]');
        End
        else
        Begin
            if(arr[2] <> arr[3]) then
                WriteLn('[3]')
            else
                WriteLn('[4]')
        End;
    End;
End.