program Project2;

{$APPTYPE CONSOLE}

uses
  SysUtils;

var
  a, b, c, d, x: extended;

begin
  readln(a, b, c, d);
  if (a = 0) and (b = 0) then
    writeln('INF')
  else
    if (a = 0) then
      writeln('NO')
    else
    begin
      x := -b / a;
      if (c * x + d = 0) then
        writeln('NO')
      else
        writeln(x:0:0);
    end;
  readln;
  readln;
end.