diff --git "a/[Lily]4-4w/[PGS]\354\210\253\354\236\220_\353\254\270\354\236\220\354\227\264\352\263\274_\354\230\201\353\213\250\354\226\264.js" "b/[Lily]4-4w/[PGS]\354\210\253\354\236\220_\353\254\270\354\236\220\354\227\264\352\263\274_\354\230\201\353\213\250\354\226\264.js"
new file mode 100644
index 0000000..255a4ee
--- /dev/null
+++ "b/[Lily]4-4w/[PGS]\354\210\253\354\236\220_\353\254\270\354\236\220\354\227\264\352\263\274_\354\230\201\353\213\250\354\226\264.js"
@@ -0,0 +1,71 @@
+function solution(s) {
+  const words = [
+    'zero',
+    'one',
+    'two',
+    'three',
+    'four',
+    'five',
+    'six',
+    'seven',
+    'eight',
+    'nine'
+  ]
+
+  const str = s.split('')
+  let word = ''
+  let answer = ''
+
+  for (let i = 0; i < str.length; i++) {
+    if (isNaN(str[i])) {
+      word += str[i]
+    } else {
+      answer += str[i]
+      continue
+    }
+
+    for (let j = 0; j < words.length; j++) {
+      if (word === words[j]) {
+        answer += j
+        word = ''
+        break
+      }
+    }
+  }
+
+  return Number(answer)
+}
+
+solution('one4seveneight')
+
+// 1. 숫자가 아니어야 한다.
+// 2. 숫자이면 탐색하지 않고 바로 answer에 넣는다.
+
+// "one4seveneight"	1478
+// "23four5six7"	234567
+// "2three45sixseven"	234567
+// "123"	123
+
+function solution(s) {
+  let numbers = [
+    'zero',
+    'one',
+    'two',
+    'three',
+    'four',
+    'five',
+    'six',
+    'seven',
+    'eight',
+    'nine'
+  ]
+
+  let answer = s
+
+  for (let i = 0; i < numbers.length; i++) {
+    let arr = answer.split(numbers[i])
+    answer = arr.join(i)
+  }
+
+  return Number(answer)
+}
diff --git "a/[Lily]4-4w/[PGS]\354\247\235\354\247\200\354\226\264_\354\240\234\352\261\260\355\225\230\352\270\260.js" "b/[Lily]4-4w/[PGS]\354\247\235\354\247\200\354\226\264_\354\240\234\352\261\260\355\225\230\352\270\260.js"
new file mode 100644
index 0000000..92e4652
--- /dev/null
+++ "b/[Lily]4-4w/[PGS]\354\247\235\354\247\200\354\226\264_\354\240\234\352\261\260\355\225\230\352\270\260.js"
@@ -0,0 +1,26 @@
+function solution(s) {
+  const stack = [0]
+
+  for (let i = 0; i < s.length; i++) {
+    if (stack[stack.length - 1] === s[i]) {
+      stack.pop()
+      continue
+    }
+
+    stack.push(s[i])
+  }
+
+  return stack.length === 1 ? 1 : 0
+}
+
+solution('baabaa')
+// return 1
+
+// 1. 문자열에서 같은 알파벳이 2개 붙어 있는 짝을 찾는다.
+// 2. 그 둘을 제거한 뒤, 앞 뒤로 문자열을 이어 붙인다.
+// 3. 위 과정을 반복한다.
+// 4. 반복 문자열을 모두 제거했다면 짝지어 제거하기가 종료된다.
+// 5. 문자열이 모두 제거되면 1, 아니면 0을 리턴한다.
+
+// 문자열이 엄청 작거나 엄청 크거나에 대해서 생각해봐야 한다.
+// 문자열이 아예 없을 수도 있다?
diff --git "a/[Lily]4-4w/[PGS]\355\201\254\352\270\260\352\260\200_\354\236\221\354\235\200_\353\266\200\353\266\204_\353\254\270\354\236\220\354\227\264.js" "b/[Lily]4-4w/[PGS]\355\201\254\352\270\260\352\260\200_\354\236\221\354\235\200_\353\266\200\353\266\204_\353\254\270\354\236\220\354\227\264.js"
new file mode 100644
index 0000000..cd075a6
--- /dev/null
+++ "b/[Lily]4-4w/[PGS]\355\201\254\352\270\260\352\260\200_\354\236\221\354\235\200_\353\266\200\353\266\204_\353\254\270\354\236\220\354\227\264.js"
@@ -0,0 +1,21 @@
+function solution(t, p) {
+  const len = p.length
+  let answer = 0
+
+  for (let i = 0; i <= t.length - len; i++) {
+    const numbers = t.slice(i, i + p.length)
+    if (+numbers <= +p) {
+      answer++
+    }
+  }
+
+  return answer
+}
+
+solution('3141592', '271')
+// solution('500220839878', '7')
+// solution('3141592', '271')
+// t	p	result
+// "3141592"	"271"	2
+// "500220839878"	"7"	8
+// "10203"	"15"	3
diff --git "a/[Lily]4w/[PGS]\355\202\244\355\214\250\353\223\234 \353\210\204\353\245\264\352\270\260.js" "b/[Lily]4w/[PGS]\355\202\244\355\214\250\353\223\234 \353\210\204\353\245\264\352\270\260.js"
new file mode 100644
index 0000000..c63a641
--- /dev/null
+++ "b/[Lily]4w/[PGS]\355\202\244\355\214\250\353\223\234 \353\210\204\353\245\264\352\270\260.js"	
@@ -0,0 +1,40 @@
+solution([1, 3, 4, 5, 8, 2, 1, 4, 5, 9, 5], 'right')
+// right
+// "LRLLLRLLRRL"
+
+function solution(numbers, hand) {
+  var answer = ''
+  const left = [1, 4, 7]
+  const right = [3, 6, 9]
+  let leftPosition = 0
+  let rightPosition = 0
+  
+  numbers.forEach(number => {
+    if (left.includes(number)) {
+      leftPosition = number
+      answer += 'L'
+      return
+    }
+    
+    if (right.includes(number)) {
+      rightPosition = number
+      answer += 'R'
+      return
+    }
+  
+    const diffLeft = Math.abs(number - leftPosition)
+    const diffRight = Math.abs(number - rightPosition)
+    
+    if (diffLeft < diffRight) {
+      answer += 'L'
+      leftPosition = number
+    } else if (diffLeft > diffRight) {
+      answer += 'R'
+      rightPosition = number
+    } else {
+      answer += hand === 'right' ? 'R' : 'L'
+    }  
+  })
+
+  return answer
+}
\ No newline at end of file