solved 3a

src/Problem3.java

@@ -0,0 +1,41 @@
+package src;
+
+import java.io.BufferedReader;
+import java.io.FileReader;
+import java.io.IOException;
+
+public class Problem3 {
+
+    public static void main(String[] args) {
+        String filePath = "inputs/inputProblem3.txt";
+        try (BufferedReader reader = new BufferedReader(new FileReader(filePath))) {
+            String line;
+            long total = 0;
+            while ((line = reader.readLine()) != null) {
+                total += maxTwoDigit(line);
+            }
+            System.out.println(total);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static int maxTwoDigit(String digits) {
+        int maxDigit = -1;
+        int maxValue = 0;
+        for (char c : digits.toCharArray()) {
+            int digit = c - '0';
+            if (maxDigit >= 0) {
+                int value = maxDigit * 10 + digit;
+                if (value > maxValue) {
+                    maxValue = value;
+                }
+            }
+            if (digit > maxDigit) {
+                maxDigit = digit;
+            }
+        }
+
+        return maxValue;
+    }
+}