function shuffle(targetList) {
  var totalCount = targetList.length
  var animal = {
    saru: 0,
    tora: 0,
    ne: 0,
    ushi: 0,
    u: 0,
    tatsu: 0,
    mi: 0,
    uma: 0,
    hitsuji: 0,
    tori: 0,
    inu: 0,
    i: 0
  }

 for (var i = 0; i < targetList.length ; i++) {
   var a = targetList[i]
   animal[a] = animal[a] + 1
 }
  
 var animalList = Object.keys(animal)
 
 var MaxCount = 0
 
 for (var i = 0; i < animalList.length ; i++) {
   var a = animalList[i]
   if (MaxCount < animal[a] ) {
     MaxCount = animal[a]
   }
 }

  var uniqueValues = totalCount - MaxCount
  
  if (MaxCount - uniqueValues >= 2) {
    console.log('NO')
  } else {
    console.log('YES')
  }
}


function Main(input) {
    var data = input.split("\n")
    shuffle(data.slice(1, data.length - 1))
}

// Don't edit this line!
Main(require("fs").readFileSync("/dev/stdin", "utf8"));