I'm usig this code, have an error runtime error (NZEC) , could, something help me with this.

import math

def Primo(num):

if num < 2:
    return False

i=2
for i in range (2,int(math.sqrt(num)+1)):
                if (num % i ==0):
                    return False
return True

def main():
a=int(input("inicio\n"))
if a == 2:
return

                b=int(input("final\n"))
                if 1<=a<=b<=1000000000:
                    if a-b<=100000:
                        for i in range (a,b):
                            if Primo(i):
                                print (i)
                else:
                    print("")

                return 0

if name == 'main':
main()