Extended Euclidean algorithm code in python

#EXTENDED EUCLIDEAN ALGORITHM TO FIND GCD(M,B)
m=int(raw_input("ENTER M OR mod M = : "))
b=int(raw_input("ENTER B = : "))
# A1,A2,A3 <---(1,0,M)
a1=1
a2=0
a3=m
# B1,B2,B3 <---(0,1,B)
b1=0
b2=1
b3=b
while 1 :
# if B3=0 return A3=GCD(M,B) and B has no inverse 
      if b3==0 :
         gcd_MB=a3
         invrs_b=0
         break
# if B3=1 return B3=GCD(M,B) and B2=B(inverse) mod M
      if b3==1 :
         gcd_MB=b3
         invrs_b=1
         break
# Q=A3/B3 
      q=a3/b3
# (T1,T2,T3) <--- [(A1-QB1),(A2-QB2),(A3-QB3)] 
      t1=a1-q*b1
      t2=a2-q*b2
      t3=a3-q*b3
# (A1,A2,A3) <--- (B1,B2,B3) 
      a1=b1
      a2=b2
      a3=b3
# (B1,B2,B3) <--- (T1,T2,T3) 
      b1=t1
      b2=t2
      b3=t3

if invrs_b==0 :
        print "\nGCD(B,M) = : ",gcd_MB,"\n"
        print "\n", b,"HAS NO MULTIPLICATIVE INVERSE IN mod",m,"\n"

if invrs_b==1 :
#FIND THE MULTIPLICATIVE INVERSE OF B IN mod M by traditional method......
        c=1    
        while ((b*c)%m)!=1 :
                            c=c+1
                            if c>m :
                                    break


#FIND MULTIPLICATIVE INVERSE OF B IN mod M BY value of b2....... 
#c=1
#while c%m!=b2 :
#            c++
#            if (c>m) :
#                  break

        if c<m :
             print  "\nGCD(B,M) = :",gcd_MB
             print  "\nMULTIPLICATIVE INVERSE OF",b, " = " ,c, " in mod",m,"\n"
        else:
             print "\nGCD(B,M) = : ",gcd_MB 
             print "\n",b," HAS NO INVERSE IN mod",m,"\n"

Compile and run in a single command :
system path> python eea.py
It will compile as well as run the program.