function RST(str){
  return str.split('').reduce((obj, val)=>{
    obj[val] = obj[val] ? obj[val]+1: 1;
    return obj;
  }, {})
}

.grid {
   display: grid;
   max-width: 200px;
   grid-template-columns: repeat(2, 1fr);
   grid-template-rows: repeat(3, auto);
   justify-items: start;
  }