diff --git a/JinHaLim/Easy/solution_1281.js b/JinHaLim/Easy/solution_1281.js
new file mode 100644
index 0000000..3a5ec8c
--- /dev/null
+++ b/JinHaLim/Easy/solution_1281.js
@@ -0,0 +1,13 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+var subtractProductAndSum = function(n) {
+    const digit = n.toString().split('').reduce((acc,curr) => {
+        acc[0] *= curr;
+        acc[1] += +curr;
+        return acc;
+    },[1,0]);
+    return digit[0] - digit[1];
+};
+console.log(subtractProductAndSum(234))
\ No newline at end of file
diff --git a/JinHaLim/Easy/solution_1342.js b/JinHaLim/Easy/solution_1342.js
new file mode 100644
index 0000000..c863f12
--- /dev/null
+++ b/JinHaLim/Easy/solution_1342.js
@@ -0,0 +1,18 @@
+/**
+ * @param {number} num
+ * @return {number}
+ */
+var numberOfSteps = function(num) {
+    let count = 0;
+    while (num !== 0) {
+        count += 1;
+        if (num % 2 === 0) {
+            num = num / 2;
+        }
+        else{
+            num -= 1;
+        }
+    }
+    return count;
+};
+console.log(numberOfSteps(14))
\ No newline at end of file
diff --git a/JinHaLim/Easy/solution_1720.js b/JinHaLim/Easy/solution_1720.js
new file mode 100644
index 0000000..924abd7
--- /dev/null
+++ b/JinHaLim/Easy/solution_1720.js
@@ -0,0 +1,14 @@
+/**
+ * @param {number[]} encoded
+ * @param {number} first
+ * @return {number[]}
+ */
+var decode = function(encoded, first) {
+    let arr = new Array(encoded.length + 1);
+    arr[0] = first;
+    encoded.forEach((v,i) => {
+        arr[i+1] = v ^ arr[i];
+    });
+    return arr;
+};
+console.log(decode([1,2,3],1))
\ No newline at end of file