01.10 c Prime numbers using sieve algorithm
01.20 c hacked by Akira KIDA, <SDI00379@niftyserve.or.jp>

10.10 s N = 1000
10.20 s count = 0
10.30 f k = 1, N; s sieve(k) = 1
10.40 f p = 2, N; do 20
10.50 t !, "Number of primes in 2..", %0.0, N, " is ", count, !
10.60 q

20.10 i sieve(p) 20.40, 20.40, 20.20
20.20 t %5.0, p; s count = count + 1
20.30 f k = p, N, p; s sieve(k) = 0
20.40 r