diff --git a/README.md b/README.md
index 7cbe511..2b85b62 100644
--- a/README.md
+++ b/README.md
@@ -9,4 +9,6 @@ Place a file called "session" with your session key cookie from https://adventof
 
 Expects runtime arguments as days, for example:
 
-"5 9 1" executes Days 5, 9, 1 in this order.
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+"5 9 1" executes Days 5, 9, 1 in this order.
+
+Add argument "T" before to use XX_testInput.txt rather than XX_input.txt
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diff --git a/src/main.cpp b/src/main.cpp
index 87a70ff..25dc12a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -50,7 +50,12 @@ int main(int argc, char *argv[]) {
 	auto days = getAllDays();
 	std::filesystem::create_directory("input");
 
-	for (int i = 1; i < argc; i++) {
+    int i = 1;
+    if (argc > 1 && std::string(argv[1]) == "T") {
+        useTestInput = true;
+        i++;
+    }
+	for (; i < argc; i++) {
 		int dayNum = std::stoi(argv[i]);
 		std::cout << "Running day " << dayNum << std::endl;
 		Input input = getInput(dayNum, key, useTestInput);
diff --git a/src/util.h b/src/util.h
index 1456762..58cd494 100644
--- a/src/util.h
+++ b/src/util.h
@@ -7,4 +7,5 @@
 #include <iostream>
 
 using std::stoi, std::to_string;
-using std::cout, std::endl;
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+using std::cout, std::endl;
+using std::string, std::vector;
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