Step 4 - Green

No need to refactor after this

Author: morph-eos

add.h

@@ -5,12 +5,17 @@
 using namespace std;
 
 int add(string numbers) {
+    char delimeter = ',';
+    if (numbers.find("//") == 0) {
+        delimeter = numbers[2];
+        numbers = numbers.substr(4);
+    }
     int sum = 0;
     stringstream ss(numbers);
     string num, strg;
     while (getline(ss, strg, '\n')) {
         stringstream lineStream(strg);
-        while (getline(lineStream, num, ',')) {
+        while (getline(lineStream, num, delimeter)) {
             sum += stoi(num);
         }
     }