/* Calculates the greatest common divisor of two numbers in
   unary representation. Default tape: gcd(6, 10) = 2. */



#define tape I I I I I I O I I I I I I I I I I

#define start_O O, right, start
#define start_I I, left , st10
/* st1_O may not happen */
#define st1_I   O, right, st2
#define st2_O   O, right, st11
#define st2_I   I, right, st3
#define st3_O   O, right, st4
#define st3_I   I, right, st3
#define st4_O   O, right, st4
#define st4_I   I, right, st5
#define st5_O   I, left , st6
#define st5_I   I, right, st5
/* st6_O may not happen */
#define st6_I   O, left , st7
#define st7_O   O, right, st13
#define st7_I   I, left , st8
#define st8_O   O, left , st9
#define st8_I   I, left , st8
#define st9_O   O, left , st9
#define st9_I   I, left , st10
#define st10_O  I, right, st1
#define st10_I  I, left , st10
#define st11_O  O, right, st11
#define st11_I  O, right, st12
#define st12_O  O, right, st16
#define st12_I  I, right, st13
#define st13_O  O, right, st14
#define st13_I  I, right, st13
#define st14_O  O, left , st_next_iteration
#define st14_I  O, right, st14
/* The state "st_next_iteration" means the the turing machine
   is about to do the next iteration of the Euklid algorithm.
   (That is, during that state, there are two numbers on the
   tape with the same gcd as the initial numbers.) */
#define st_next_iteration_O  O, left , st_next_iteration
#define st_next_iteration_I  I, left , st8
#define st16_O  O, right, stop
#define st16_I  O, right, st16