What sign is called "An obstacle bypass on the left"?

Erklärung
Sign 3 is the round blue sign with a straight white arrow pointing down-left; it directs traffic to pass along the left side of an obstruction located on the carriageway. Sign 1 requires a left turn at a junction, sign 2 warns of a left bend, and signs 4 and 5 direct traffic along a detour around a closed road section, so none serves as an obstacle-bypass instruction.