diff --git a/src/problem1.js b/src/problem1.js
index 9a14f2c..3eeb061 100644
--- a/src/problem1.js
+++ b/src/problem1.js
@@ -1,6 +1,53 @@
 function problem1(pobi, crong) {
-  var answer;
-  return answer;
-}
+  let Add = 0;
+  let Mul = 1;
+  let pobi_max;
+  let crong_max;
+  
+  if(pobi[0]!==pobi[1]-1 || crong[0]!==crong[1]-1)
+    return -1;
+
+  function name(arr){
+    for (let i=0; i<2; i++ ){
+      let Max = 0;
+      
+      let n=arr[i].toString();
+      
+      for(let j of n){
+        Add += Number(j);
+        Mul *= Number(j);
+      }
+      if(Add>Mul)
+        arr[i]=Add;
+      
+      else 
+        arr[i]=Mul;
+      
+      Add = 0;
+      Mul = 1;
+  }
+
+  if(arr[0]>arr[1])
+    Max = arr[0];
+  else 
+    Max = arr[1];
+
+  return Max;
+
+  }
+
+  pobi_max = name(pobi);
+  crong_max = name(crong);
+
+  if(pobi_max>crong_max)
+    return 1;
+  else if(crong_max>pobi_max)
+    return 2;
+  else if(crong_max==pobi_max) 
+    return 0;
+
+
+}  
+
 
 module.exports = problem1;
diff --git a/src/problem2.js b/src/problem2.js
index cebd07c..cba97a2 100644
--- a/src/problem2.js
+++ b/src/problem2.js
@@ -1,6 +1,29 @@
 function problem2(cryptogram) {
-  var answer;
-  return answer;
+  
+  let arr = cryptogram.split("");
+  var cnt;
+  
+  while(true){
+
+    let cnt = true;
+    
+    for(let i=0;i<arr.length-1;i++){
+      if(arr[i]==arr[i+1])
+      {
+        arr.splice(i,2);
+        cnt = false;
+        break;
+      }
+      cnt = true;
+    }
+    n = arr.length;
+    if(cnt || n == 0)
+      break;
+  }
+  
+  let str = arr.join("")
+  return str;
+
 }
 
 module.exports = problem2;
diff --git a/src/problem3.js b/src/problem3.js
index 1baed28..48a0997 100644
--- a/src/problem3.js
+++ b/src/problem3.js
@@ -1,6 +1,22 @@
 function problem3(number) {
-  var answer;
-  return answer;
+  
+  let cnt=0;
+  for(let i=1;i<=number;i++){
+    let arr=i.toString().split("");
+    for(let j=0;j<arr.length;j++){
+      if(arr[j]==3){
+        cnt++;
+      }
+      else if(arr[j]==6){
+        cnt++;
+      }
+      else if(arr[j]==9){
+        cnt++;
+      }
+    }
+  }
+
+  return cnt;
 }
 
 module.exports = problem3;
diff --git a/src/problem4.js b/src/problem4.js
index ee1d3bd..b93a28c 100644
--- a/src/problem4.js
+++ b/src/problem4.js
@@ -1,6 +1,18 @@
 function problem4(word) {
-  var answer;
-  return answer;
+  let arr = Array.from(word);
+
+for (let i = 0; i < arr.length; i++) {
+  let ascii = arr[i].charCodeAt(0);  
+  if (ascii >= 65 && ascii <= 90) {  
+    arr[i] = String.fromCharCode(155 - ascii);
+  } else if (ascii >= 97 && ascii <= 122) {  
+    arr[i] = String.fromCharCode(219 - ascii);
+  }
+}
+
+let result = arr.join(''); 
+return result;
+
 }
 
 module.exports = problem4;
diff --git a/src/problem5.js b/src/problem5.js
index 9368e87..1431094 100644
--- a/src/problem5.js
+++ b/src/problem5.js
@@ -1,6 +1,17 @@
 function problem5(money) {
-  var answer;
-  return answer;
+    let arr = [50000, 10000, 5000, 1000, 500, 100, 50, 10, 1];
+    let result = [];
+
+
+
+    for(let i of arr){
+        result.push(Math.floor(money/i));
+        money = money % i;
+
+    }
+
+    return result;
+
 }
 
 module.exports = problem5;