Erdős Number

As per Wikipedia, the Erdős number describes the collaborative distance between mathematician Paul Erdős and another person, as measured by authorship of mathematical papers.

As per this portal by the American Mathematical Sciety, my Erdős number is 4:

Umang Mathur Shankara Narayanan Krishna Weak Singular Hybrid Automata
Shankara Narayanan Krishna Marian Gheorghe On Restricted Bio-Turing Machines
Marian Gheorghe Solomon Marcus Special Issue Natural Computing: Theory and Applications
Solomon Marcus Paul Erdős Sur la décomposition de l'espace euclidien en ensembles homogènes