function clickToShow(elementClick, elementShow){
var elButton = document.querySelector(elementClick);
var elShow = document.querySelector(elementShow);
elButton.addEventListener("click", function(event) {
elShow.classList.add("show");
});
}
clickToShow('#London','#London h2');
clickToShow('.house-base-buy','.house-base');
clickToShow('.house-walls-buy','.house-walls');