diff --git a/src/main/java/io/zipcoder/Problem1.java b/src/main/java/io/zipcoder/Problem1.java
index 6cd6024..be4f9f3 100644
--- a/src/main/java/io/zipcoder/Problem1.java
+++ b/src/main/java/io/zipcoder/Problem1.java
@@ -1,4 +1,41 @@
 package io.zipcoder;
 
+import javax.swing.text.html.HTMLDocument;
+import java.util.*;
+
 public class Problem1 {
+    public String toreplaceChar(String input) {
+
+        String input2 = input.toLowerCase();
+
+        HashMap<Character, Character> toReplace = new HashMap<Character, Character>();
+        toReplace.put('f' , '7');
+        toReplace.put('s' , '$');
+        toReplace.put('1' , '!');
+        toReplace.put('a' , '@');
+
+        char[] inputArray = input.toCharArray();
+
+
+        for (int i = 0; i < inputArray.length; i++) {
+
+            if (toReplace.containsKey(input.toLowerCase().charAt(i)))
+                inputArray[i] = toReplace.get(input2.charAt(i));
+        }
+
+        return new String(inputArray);
+    }
 }
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/src/test/java/io/zipcoder/Problem1Test.java b/src/test/java/io/zipcoder/Problem1Test.java
index de82e99..7640f42 100644
--- a/src/test/java/io/zipcoder/Problem1Test.java
+++ b/src/test/java/io/zipcoder/Problem1Test.java
@@ -1,4 +1,22 @@
 package io.zipcoder;
 
+import org.junit.Assert;
+import org.junit.Test;
+
+
 public class Problem1Test {
+
+
+    Problem1 problem1 = new Problem1();
+    @Test
+    public void replaceKey() throws Exception {
+
+
+        String expected = "The 7@rmer went to the $tore to get ! doll@r’$ worth o7 7ertilizer";
+
+        String actual = problem1.toreplaceChar("The Farmer went to the store to get 1 dollar’s worth of fertilizer");
+
+        Assert.assertEquals(expected, actual);
+
+    }
 }