What is in this test and what is wright answer?

var  n,m,y,i,x,j:longint;
   yes:boolean;
begin
    read(n,m,y);
    yes:=false;
    for i:=0 to m-1 do
    begin
        x:=i;
        if (n=0)then x:= 1;
        for j:=2 to n do
            x:=(x*i) mod m;
        if x mod m=y then
        begin
            yes:=true;
            write(i,' ');
        end;
    end;
    if yes=false then write('-1');
end.