Logic Masters Deutschland e.V.

In preparation for this years german logic puzzle championship, I constructed a few puzzles which will be put online in the next few weeks.

Rules: Draw a closed loop that goes through every region exactly once. Numbers indicate the number of cells a loop visits in each region. Empty cells of different regions cannot touch orthogonally. The loop cannot go through crosses. Exactly one of the given numbers is a liar that cannot be true everywhere it appears. It is part of the puzzle to identify the lying number.