Pascal :

var
  max,len,n:int64;
  i,j:longint;
  w,v,f:array[0..1000]of extended;
  minv,t:extended;
begin
  read(max,len,n);
  for i:=1 to n do read(w[i],v[i]);
  f[0]:=0;
  f[1]:=len/v[1];
  for i:=2 to n do begin
    f[i]:=1e24;
    minv:=1e24;
    t:=0;
    for j:=i downto 1 do begin
      t:=t+w[j];
      if v[j]<minv then minv:=v[j];
      if t>max then break;
      if minv<>0 then
			  if f[j-1]+len/minv<f[i] then f[i]:=f[j-1]+len/minv;
    end
  end;
  write(f[n]*60:0:1);
end.