diff --git a/code_study/Baekjoon/js/10809.js b/code_study/Baekjoon/js/10809.js
new file mode 100644
index 0000000..fdf7b9e
--- /dev/null
+++ b/code_study/Baekjoon/js/10809.js
@@ -0,0 +1,8 @@
+const s = require("fs").readFileSync(0, "utf8").toString().trim();
+let arr = new Array(26).fill(-1);
+for(let i=0; i<s.length; i++){
+    if(arr[s[i].charCodeAt()-97]==-1){
+        arr[s[i].charCodeAt()-97] = i;
+    }
+}
+console.log(...arr);
\ No newline at end of file
diff --git a/code_study/Baekjoon/js/1152.js b/code_study/Baekjoon/js/1152.js
new file mode 100644
index 0000000..82664d2
--- /dev/null
+++ b/code_study/Baekjoon/js/1152.js
@@ -0,0 +1,2 @@
+const s = require("fs").readFileSync(0, "utf8").toString().trim().split(" ");
+console.log(s[0]=="" ? 0 : s.length);
\ No newline at end of file
diff --git a/code_study/Baekjoon/js/11654.js b/code_study/Baekjoon/js/11654.js
new file mode 100644
index 0000000..59b91fd
--- /dev/null
+++ b/code_study/Baekjoon/js/11654.js
@@ -0,0 +1 @@
+console.log(require("fs").readFileSync(0, "utf8").toString().trim().charCodeAt());
\ No newline at end of file
diff --git a/code_study/Baekjoon/js/11718.js b/code_study/Baekjoon/js/11718.js
new file mode 100644
index 0000000..3d6a954
--- /dev/null
+++ b/code_study/Baekjoon/js/11718.js
@@ -0,0 +1 @@
+console.log(require("fs").readFileSync(0, "utf8").toString().trim());
\ No newline at end of file
diff --git a/code_study/Baekjoon/js/11720.js b/code_study/Baekjoon/js/11720.js
new file mode 100644
index 0000000..31ddc81
--- /dev/null
+++ b/code_study/Baekjoon/js/11720.js
@@ -0,0 +1,6 @@
+const n = require("fs").readFileSync(0, "utf8").toString().trim().split("\n");
+let sum =0;
+for(let i=0; i<Number(n[0]); i++){
+    sum += Number(n[1][i]);
+}
+console.log(sum)
\ No newline at end of file
diff --git a/code_study/Baekjoon/js/2675.js b/code_study/Baekjoon/js/2675.js
new file mode 100644
index 0000000..a366aa9
--- /dev/null
+++ b/code_study/Baekjoon/js/2675.js
@@ -0,0 +1,9 @@
+const n = require("fs").readFileSync(0, "utf8").toString().trim().split("\n");
+for(let i=1; i<=Number(n[0]); i++){
+    let temp = "";
+    [x, s] = n[i].split(" ");
+    for(let ii=0; ii<s.length; ii++){
+        temp += s[ii].repeat(Number(x));
+    }
+    console.log(temp);
+}
diff --git a/code_study/Baekjoon/js/2743.js b/code_study/Baekjoon/js/2743.js
new file mode 100644
index 0000000..bbadf93
--- /dev/null
+++ b/code_study/Baekjoon/js/2743.js
@@ -0,0 +1 @@
+console.log(require("fs").readFileSync(0, "utf8").toString().trim().length);
\ No newline at end of file
diff --git a/code_study/Baekjoon/js/27866.js b/code_study/Baekjoon/js/27866.js
new file mode 100644
index 0000000..2ba1b3d
--- /dev/null
+++ b/code_study/Baekjoon/js/27866.js
@@ -0,0 +1,2 @@
+const n = require("fs").readFileSync(0, "utf8").toString().split("\n");
+console.log(n[0][Number(n[1])-1])
\ No newline at end of file
diff --git a/code_study/Baekjoon/js/2908.js b/code_study/Baekjoon/js/2908.js
new file mode 100644
index 0000000..f3b9eb3
--- /dev/null
+++ b/code_study/Baekjoon/js/2908.js
@@ -0,0 +1,4 @@
+const n = require("fs").readFileSync(0, "utf8").toString().split(" ");
+const a = Number(n[0].split("").reverse().join(""));
+const b = Number(n[1].split("").reverse().join(""));
+console.log(a>b?a:b);
diff --git a/code_study/Baekjoon/js/5622.js b/code_study/Baekjoon/js/5622.js
new file mode 100644
index 0000000..22c4736
--- /dev/null
+++ b/code_study/Baekjoon/js/5622.js
@@ -0,0 +1,7 @@
+const s = require("fs").readFileSync(0, "utf8").toString().trim();
+const dial = [3,3,3,4,4,4,5,5,5,6,6,6,7,7,7,8,8,8,8,9,9,9,10,10,10,10];
+let t = 0;
+for(let i=0; i<s.length;i++){
+    t += dial[s[i].charCodeAt()-65];
+}
+console.log(t);
\ No newline at end of file
diff --git a/code_study/Baekjoon/js/9086.js b/code_study/Baekjoon/js/9086.js
new file mode 100644
index 0000000..56ef6c6
--- /dev/null
+++ b/code_study/Baekjoon/js/9086.js
@@ -0,0 +1,5 @@
+const n = require("fs").readFileSync(0, "utf8").toString().trim().split("\n");
+for(let i=1; i<=Number(n[0]); i++){
+    s = n[i];
+    console.log("%s%s",s[0],s[s.length-1]);
+}
\ No newline at end of file