function sieve(n) begin
    prime = [true]*(n+1)
    p = 2
    while p*p <= n begin
        if prime[p] then for i=p*2 to n-p+1 step p begin
            prime[i] = false
        end
        p += 1
    end
    for p=2 to n then if prime[p] then print(p, " ")
end
sieve(10000)
print("\n")