modexp

def GCD(a,b):
   if a == 0:
      return b
   if b == 0:
      return a
   if a < b:
      return GCD(a,b%a)
   else:
      return GCD(a%b,b)

def ord(n,r):
   val = GCD(n,r)
   if val != 1:
      print("error: not co-prime.", val)
      return 0
   value = n
   k = 1
   while value != 1:
      value *= n
      value = value%r
      k += 1
   return k

def multexp(terms, exp, modpoly, reduce):
    prev = terms[:]
    while exp > 1:
       axillary = [0]*(len(prev)+len(terms)-1)
       for i in range(0, len(terms)):
          for j in range(0, len(prev)):
             axillary[i+j] += terms[i]*prev[j]
       print(axillary)
       for i in range(0,len(axillary)-len(modpoly)+1):
          temp = axillary[i]
          for j in range(0,len(modpoly)):
             axillary[j+i] -= modpoly[j]*temp
       print(axillary)
       for i in range(0,len(axillary)):
          axillary[i] = axillary[i]%reduce
       while axillary[0] == 0:
          axillary.pop(0)
       prev = axillary[:]
       exp -= 1
    return prev