https://google.ru/search?q=exp(-((x-4)^2%2B(y-4)^2)^2/1000)+%2B+exp(-((x+%2B4)^2%2B(y%2B4)^2)^2/1000)+%2B+0.1exp(-((x+%2B4)^2%2B(y%2B4)^2)^2)%2B0.1exp(-((x+-4)^2%2B(y-4)^2)^2)&ie=utf