domaci 3

program treci;

var m,n,i,maxrast,pp,r1,r2:integer;

function prost(n:integer):boolean;
var d:integer; rez:boolean;
begin
    rez:=(n=2) or ((n mod 2=1) and (n>1));
    d:=3;
    while ((d*d<=n) and rez) do
        begin
        rez:=rez and (n mod d<>0);
        d:=d+2;
        end;
    prost:=rez;
end;

begin
write('interval u kome se traze prosti brojevi: ');
readln(m,n);
maxrast:=0;
pp:=0;
r1:=0;
r2:=0;
i:=m;
while i<=n-maxrast do
    begin
        if prost(i)
        then begin
            pp:=i;
            i:=i+1;
            while(i<=n) do
            begin
                if prost(i)
                then begin
                    if (maxrast<=(i-pp))
                    then begin
                        r1:=pp;
                        r2:=i;
                        maxrast:=i-pp;
                    end;
                    pp:=i;
                end;
                i:=i+1;
            end;
                if r2<>0 then writeln(r1,', ',r2)
        end;
        i:=i+1;
    end;
if(r2=0) and (pp<>0) then writeln('samo jedan prost')
else if (r2=0) and (r1=0) then writeln('nema prostih');

readln;
end.