program cell;
var a,b,p:array[0..50000]of longint;
    mid,ced:array[0..5000]of longint;
    t,k,m,n,i,j,x,y,mini,zz,m1,m2:longint;
procedure prime;
var t,k:longint;
begin
p[1]:=2;
p[2]:=3;
p[3]:=5;
j:=3;
for t:=5 to 50000 do
  if (t mod 2>0)and(t mod 3>0)and(t mod 5>0)and(b[t]=0) then
    begin
      inc(j);
      p[j]:=t;
      for k:=1 to 50000 div t do
        b[t*k]:=1;
    end;
end;
procedure fenjie1(i:longint);
var t,k,o:longint;
begin
k:=0;
o:=i;
repeat
  inc(k);
  if o mod p[k]=0 then
    repeat
      o:=o div p[k];
      inc(mid[k]);
    until o mod p[k]<>0;
until o=1;
mid[0]:=k;
end;
procedure fenjie2(i:longint);
var t,k,o:longint;
begin
fillchar(ced,sizeof(ced),0);
k:=0;
o:=i;
repeat
  inc(k);
  if o mod p[k]=0 then
    repeat
      o:=o div p[k];
      inc(ced[k]);
    until o mod p[k]<>0;
until (o=1)or(k>mid[0]);
ced[0]:=k;
end;
function min(x,y:longint):longint;
begin
if x>y then min:=y else  min:=x;
end;
function max(x,y:longint):longint;
begin
if x>y then max:=x else  max:=y;
end;
function gcd(x,y:longint):longint;
var t,k,a,b:longint;
begin
t:=max(x,y);
k:=min(x,y);
repeat
  i:=k;
  a:=t mod k;
  b:=t div k;
  t:=max(a,b);
  k:=min(a,b);
until a=0;
gcd:=i;
end;
procedure ppit;
var t,k,x,y:longint;
begin
x:=0;
if ced[0]>=mid[0] then
  begin
    for t:=1 to mid[0] do
      if mid[t]>0 then
        begin
          if ced[t]=0 then exit;
          if (mid[t]div ced[t]>x)and(mid[t]mod ced[t]=0) then
            x:=mid[t]div ced[t]
          else if(mid[t]div ced[t]+1>x)and(mid[t]mod ced[t]>0) then
            x:=mid[t]div ced[t]+1
        end;
    zz:=x;
  end;
end;

begin
assign(input,'cell.in');
reset(input);
assign(output,'cell.out');
rewrite(output);
readln(n);
readln(m1,m2);
if (m1=1)and(m2=1) then
  begin
    writeln(0);
    close(output);
    halt;
  end;
for t:=1 to n do
  read(a[t]);
prime;
fenjie1(m1);
for t:=1 to mid[0] do
  mid[t]:=mid[t]*m2;
for t:=1 to n do
  begin
    fenjie2(a[t]);
    ppit;
    if (zz<mini)or(mini=0) then mini:=zz;
  end;
if mini=0 then
  mini:=-1;
writeln(mini);
close(output);
end.