# this program is deterministic and really does terminate.
# who wrote this bizarre program? (oops, I did.)
resource do7()
	int  m = 4; const int N = 3
	int a,b,c,d; int  e = m; int f = N
	a = 8888
	b = 7777
	c = 6666
	d = 1
	write(a); write(b); write(c); write(d)
	while (true) {
	    if (a == 1) {
		writes("\nA")
		a :=: b
	    } else if (b == 1 ) {
		writes("\nB")
		b :=: d
	    } else if (c == 1 ) {
		writes("\nC")
		if (e == 0) {
			if (f > 0) {
				c :=: a
				e = m
				m = m-1
				f = f-1
			} else { c = 9999
			}
		} else { e--
		}
	    } else if (d == 1 ) {
		writes("\nD")
		d :=: c
	    } else {
		exit
	    }
	}
	write(a); write(b); write(c); write(d)
	write(e); write(f)
end