setInterval(function(){
for(var pp = 0; pp < letters_word1.length; pp++){
setTimeout(function(){
if(letters_word1[y] == undefined) y = 0;
letters_word1[y].classList.toggle("active");
y++;
}, 100 * pp);
}
for(var pp = 0; pp < letters_word2.length; pp++){
setTimeout(function(){
if(letters_word2[l] == undefined) l = 0;
letters_word2[l].classList.toggle("active");
l++;
}, 100 * pp);
}
}, 4000);