2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/5925It is shown that using the observed extensive air shower (EAS) electron and truncated muon size spectra at sea level one can solve the EAS inverse problem - reconstruction of primary energy spectra and elemental composition, for not more than 2 kinds of primary nuclei.Submitted to 28th ICRC (Tsukuba, Japan), 6 pages, 2 figuresAstrophysicstext