シクシク素数列 (Pascal)

シクシク素数列	https://qiita.com/advent-calendar/2018/4949prime-series
Crystal	https://qiita.com/cielavenir/items/4c95fdf14b7a247e51e0
Kuin	https://qiita.com/cielavenir/items/60993a2b2885690a3a4a
Swift	https://qiita.com/cielavenir/items/db4c93532a53bfa33ac2
Kotlin	https://qiita.com/cielavenir/items/f3ccdd5ebf245aba417c
Pascal	https://qiita.com/cielavenir/items/4c962db6825d9a5eb511

4949.pas

program sksk;
var i,n,cnt: longint;

function isqrt(n: longint): longint;
var
    x: longint;
    y: longint;
begin
    if(n<=0) then
        isqrt:=0
    else if(n<4) then
        isqrt:=1
    else begin
        x:=0;
        y:=n;
        while((x<>y) and (x+1<>y)) do begin
            x:=y;
            y:=(n div y+y) div 2;
        end;
        isqrt:=x;
    end;
end;

function isPrime(i: longint): boolean;
var
    j: longint;
begin
    isPrime:=true;
    if i<2 then isPrime:=false;
    for j:=2 to isqrt(i) do begin
        if(i mod j < 1) then
            isPrime:=false;
    end;
end;

function is4949(i: longint): boolean;
begin
    if(i <= 0) then
        is4949:=false
    else if( (i mod 10 = 4)or(i mod 10 = 9) ) then
        is4949:=true
    else
        is4949:=is4949(i div 10);
end;

begin
    read(n);
    i:=2;
    cnt:=0;
    while(cnt<n) do begin
        if(is4949(i) and isPrime(i)) then begin
            write(i);
            if(cnt < n - 1) then
                write(',')
            else
                writeln();
            cnt:=cnt + 1;
        end;
        i:=i + 1;
    end;
end.