German Chancellor Angela Merkel (R) and Baden-Wuerttemberg's Prime Minister Winfried Kretschmann of Germany's environmental party Die Gruenen (The Greens) arrive for the 23rd German Unification Day festivities in Stuttgart October 3, 2013.Merkel is due to hold preliminary talks with the Social Democrats (SPD) on Friday and the Greens late next week to assess whether there is enough common ground to enter formal coalition negotiations with either party. REUTERS/Michael Dalder (GERMANY - Tags: POLITICS)