Намиране на НОД на-голям общ делител в c++

#include <iostream.h>

int a,b,c;

void main() {

cout<<"vavedete a = ";

cin>>a;

cout<<"vavedete b = " ;

cin>>b;

cout<<"A="<<a<<" B="<<b<<"\n";

x : if (a==b)

{

cout<<"NOD="<<a;



}

else

if (a<b)

{

c=a;

a=b;

b=c; goto x1;

}

else {

x1 : a=a-b;

cout<<"A="<<a<<" B="<<b<<"\n";

goto x;

}

}