 Complete the following phrase:  The 3rd Army, with support of the German South Army, spearheaded the offensive against Russian positions in the Carpathian Mountains in January 1915 in an attempt to reverse the losses during last years Galicia debacle. By then it had been built up to include fifteen infantry and four and a half cavalry divisions for the assault, which began on January 23 with the goal of securing the rail and communications hubs of Medzilaborce, Sambir, and Sanok. Despite some early successes against numerically inferior enemy units which allowed them to advance about 38 kilometers, the Habsburg troops suffered from a lack of reinforcements and logistical problems. The mountain winter weather also turned for the worse as the overstretched 3rd Army had to defend its line from Russian counteroffensives, as it occupied a large gap between two important passes on January 26. By early February, the Austro-Hungarian offensive had stalled without reaching the 