diff --git a/02_MENT/a.out b/02_MENT/a.out
new file mode 100755
index 0000000..aacdc59
Binary files /dev/null and b/02_MENT/a.out differ
diff --git a/02_MENT/build.sh b/02_MENT/build.sh
old mode 100644
new mode 100755
index 04a14d3..7efe4e7
--- a/02_MENT/build.sh
+++ b/02_MENT/build.sh
@@ -1,3 +1,10 @@
 #!/bin/bash
-clang++ -std=c++14 -I../helpers/  -o limits.out limits_println.cpp 
-clang++ -std=c++14 -I../helpers/  -o println.out printlnDemo.cpp 
+
+rm *.out
+
+clang++-6.0 -std=c++14 -I../helpers/  -o limits.out limits_println.cpp 
+clang++-6.0 -std=c++14 -I../helpers/  -o println.out printlnDemo.cpp 
+
+clang++-6.0 -std=c++14 main_02_MENT.cpp
+
+./a.out
diff --git a/02_MENT/limits.out b/02_MENT/limits.out
new file mode 100755
index 0000000..e3a35a4
Binary files /dev/null and b/02_MENT/limits.out differ
diff --git a/02_MENT/main_02_MENT.cpp b/02_MENT/main_02_MENT.cpp
index caa166f..faf6262 100644
--- a/02_MENT/main_02_MENT.cpp
+++ b/02_MENT/main_02_MENT.cpp
@@ -1,31 +1,43 @@
 // file: main_02_MENT.cpp
 // THIS IS C++, use clang++
 
-#include "../helpers/println.hpp"
 #include <iostream>
 
+#include "../helpers/println.hpp"
+
 struct PascalString{
 	int length;            // number of chars used
 	char characters[256];  // chars of some character string
 };
 
-int hexDigitToInt(char hexDigit){
-int value = -1;
-// TBD
+int hexDigitToInt(char hexDigit) {
+int value = 0;
+
+if(hexDigit > 47 && hexDigit < 58)
+    value = hexDigit - 48;
+
+if(hexDigit > 96 && hexDigit < 103)
+    value = hexDigit - 97 + 10;
+
 return value;
 }
 
-int hexStringToInt(PascalString binaryDigits){
+int hexStringToInt(PascalString binaryDigits) {
 int returnValue = -1;
 
 return returnValue;
 }
 
-int main(int argc, char** argv, char** envp){
+int main(int argc, char** argv, char** envp) {
 	PascalString s = {3, '1', '0', '0'};
 	PascalString s2 = {4, 'f', 'f', 'f', 'f'};
   println(hexStringToInt(s));
   println(hexStringToInt(s2));
+
+  
+  println(hexDigitToInt('D'));
+  println(hexDigitToInt('9'));
+  println(hexDigitToInt('2'));
   	return 0;
 }
 
diff --git a/02_MENT/println.out b/02_MENT/println.out
new file mode 100755
index 0000000..82e5fb3
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