Extended Euclidean algorithm code in C

/*EXTENDED EUCLIDEN ALGORITHM FOR FIND GCD OF TWO NUMBERS */
#include < stdio.h >
main(){
int m,b,a1,a2,a3,b1,b2,b3,gcd_MB,invrs_b,q,t1,t2,t3;
char ch='a';
while(ch!='q'){
printf("ENTER M OR mod M= : ");
scanf("%d",&m);
printf("ENTER B = : ");
scanf("%d",&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){
printf("\nGCD(B,M) = : %d",gcd_MB);
printf("\n %d HAS NO MULTIPLICATIVE INVERSE IN mod %d \n",b,m);
}
if(invrs_b==1)
{
/*FIND THE MULTIPLICATIVE INVERSE OF B
 IN mod M by traditional method......*/
int c=1;
while(((b*c)%m)!=1)
{
c++;
if(c>m)
break;
}

/*FIND MULTIPLICATIVE INVERSE OF B IN mod M BY value of b2 
int c=1;
while(c%m!=b2){
c++;
if(c>m)
break;
}*/
if(c < m)
{
printf("\nGCD(B,M) = : %d",gcd_MB);
printf("\nMULTIPLICATIVE INVERSE OF %d = %d in mod %d\n",b,c,m);
}
else
{
printf("\nGCD(B,M) = : %d",gcd_MB); 
printf("\n %d HAS NO INVERSE IN mod %d\n",b,m);
}}
scanf("%c",&ch);
}
}

Compile in LINUX environment by:
Compile : gcc -o eea eea.c
Run     :./eea
here gcc is a c/c++ compiler and eea.c is a c sourcecode file.