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var a,b,c:array[1..50]of longint;
    f:array[0..100000]of int64;
    n,i,j,t,t1,ans:longint;
function max(x,y:int64):int64;
begin
  if x>y then exit(x)
         else exit(y);
end;
begin
  readln(t,n);
  for i:=1 to n do
    read(a[i]);
  for i:=1 to n do
    read(b[i]);
  for i:=1 to n do
    read(c[i]);
  for i:=1 to n-1 do
    for j:=i+1 to n do
    begin
      if c[i]*b[j]>c[j]*b[i] then
      begin
        t1:=a[i];
        a[i]:=a[j];
        a[j]:=t1;
        t1:=b[i];
        b[i]:=b[j];
        b[j]:=t1;
        t1:=c[i];
        c[i]:=c[j];
        c[j]:=t1;
      end;
    end;
  for i:=1 to n do
    for j:=t downto c[i] do
      f[j]:=max(f[j],f[j-c[i]]+a[i]-b[i]*(t-j));
  for i:=1 to t do
    ans:=max(ans,f[i]);
  writeln(ans);
end.