use(io). print_primes_upto(max:val(int)):expr(void)=( is_prime:var(bool^eval(max+1)) . clear_multiples(x:val(int)):expr(void)=( n:var(int). n:=2*x; while (n<=max) do ( is_prime[n]:=false; n:=n+x ) ). i:var(int). forseq i in 1 to max do is_prime[i]:=true; forseq i in 2 to max do if (is_prime[i]) then ( print(i); print(" is prime\n"); clear_multiples(i) ) ). x:var(int). print("Enter max number:\n"); x:=readint; print_primes_upto(x)