diff --git a/src/xs_ibdpcompsci_javaintro/practice1.java b/src/xs_ibdpcompsci_javaintro/practice1.java
deleted file mode 100644
index f853121..0000000
--- a/src/xs_ibdpcompsci_javaintro/practice1.java
+++ /dev/null
@@ -1,66 +0,0 @@
-package xs_ibdpcompsci_javaintro;
-import java.util.*;
-
-class RPN_Calculator {
-    static ArrayList<Object> request_input() {
-		Scanner input = new Scanner(System.in);
-		
-		// Initialize variables. 
-		ArrayList<Object> USER_INPUTS = new ArrayList<Object>();
-		String USER_INPUT_CURRENT = "";
-		Boolean USER_INPUT_MORE = true;
-		
-		// Loop for input. 
-		do {
-			USER_INPUT_CURRENT = input.nextLine();
-
-			if (USER_INPUT_CURRENT.isEmpty() || USER_INPUT_CURRENT.isBlank()) {
-				USER_INPUT_MORE = false;
-			} else if (USER_INPUT_CURRENT.matches("-?\\d+(\\.\\d+)?")) {
-				USER_INPUTS.add(Float.parseFloat(USER_INPUT_CURRENT));
-			} else {
-				if (USER_INPUT_CURRENT.matches("[+\\-*\\/^]") && (USER_INPUTS.size() > 2)) {
-					USER_INPUTS.add(USER_INPUT_CURRENT);
-				} else if (USER_INPUT_CURRENT.toLowerCase() == "exit") {
-					System.exit(0);
-				} else {
-					// The user inputs a wrong code. Let the user edit it. 
-					System.out.println("\\033[A");
-				};
-			};
-		} while (USER_INPUT_MORE == true);
-
-		input.close();
-		return (USER_INPUTS);
-	}
-	
-	static float calculate(ArrayList<Object> ENTRIES_LIST, String OPERATION) {
-		// Calculate length. 
-		int ENTRIES_LIST_LENGTH = ENTRIES_LIST.size();
-
-		float OPERATION_RESULT = (float) ENTRIES_LIST.get(0);
-
-		if (ENTRIES_LIST_LENGTH > 1) {
-			for (int ENTRY_CURRENT = 1; ENTRY_CURRENT < ENTRIES_LIST_LENGTH; ENTRY_CURRENT++) {
-				if (OPERATION == "+") {
-					OPERATION_RESULT += (float) ENTRIES_LIST.get(ENTRY_CURRENT);
-				} else if (OPERATION == "-") {
-					OPERATION_RESULT -= (float) ENTRIES_LIST.get(ENTRY_CURRENT);
-				};
-			};
-		};
-
-		return (OPERATION_RESULT);
-	};
-	
-	
-	public static void main(String[] args) {
-		// Initialize the input numbers. 
-		ArrayList<Object> NUMBERS_INPUT = new ArrayList<Object>();
-		while (true) {
-			NUMBERS_INPUT = request_input();
-			
-
-		}
-    }
-}
\ No newline at end of file