diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..723ef36
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.idea
\ No newline at end of file
diff --git a/Problem1.java b/Problem1.java
index 8b13789..01f2a12 100644
--- a/Problem1.java
+++ b/Problem1.java
@@ -1 +1,40 @@
+// [1, 2, 3, 4, 6, 7, 8]
 
+// Time complexity : O(logn)
+// Space complexity : O(1)
+class Solution {
+    public static void main(String[] args) {
+
+        Solution s = new Solution();
+        System.out.println(s.helper(new int[]{1, 2, 3, 4, 6, 7, 8}));
+    }
+
+    private int helper(int[] input) {
+
+        // null condition
+        if(input.length == 0) {
+            System.out.println("No elements in the array");
+        }
+
+        int low = 0, high = input.length - 1;
+
+        while(low <= high) {
+
+            int mid = low + (high - low)/2;
+
+            // element condition
+            if(input[mid] - mid == 2) {
+                return mid + 1;
+            }else if(input[mid] - mid == 1) {
+                // element on the right side
+                // System.out.println(low + " " + "low")
+                low = mid;
+            } else {
+                // element on the left side
+                high = mid;
+            }
+        }
+
+        return -1;
+    }
+}