def argument_test_natural_number( )def helper( )if type(xis int and return (xelseraise exception("argument is not an integer"return helper @argument_test_natural_number def factorial( )if = return elsereturn *factorial( - factorial( out[ ] in [ ]factorial(- exception traceback (most recent call lastin ---- factorial(- in helper( return ( else---- raise exception("argument is not an integer" return helper exceptionargument is not an integer in [ ]def sum_aritmetic_series( )return *( + )/ sum_aritmetic_series( out[ ] in [ ]sum_aritmetic_series( out[ ] in [ ]@argument_test_natural_number def sum_aritmetic_series( )return *( - )/ sum_aritmetic_series( out[ ]