The compound shown has several nitrogen atoms. Count the nitrogen atoms whose lone pair can accept a proton from dilute acid. Treat as non-basic any nitrogen whose lone pair is delocalised into a pi system (amide N, N attached directly to the electron-poor pyridine ring); the in-plane lone pair of a pyridine-type ring nitrogen counts as available. Give the answer as an integer.

Numerical answer type, tolerance 0.5.