diff --git a/README.md b/README.md
index eefd222..d97f036 100644
--- a/README.md
+++ b/README.md
@@ -10,12 +10,11 @@ classDiagram
         + void run()
     }
     class Memory {
-        + abstract Word read(Address address)
-        + abstract int size()
-        + abstract void write(Address address, Word data)
-        + abstract void dump()
+        + Word read(Address address)
+        + int size()
+        + void write(Address address, Word data)
+        + void dump()
     }
-    class Program
     class ProgramCounter {
         - int PC
         - int SysTick
@@ -29,32 +28,10 @@ classDiagram
         + boolean halted()
         + void halt()
     }
-    class Instruction {
-        + abstract void execute(Memory memory, ProgramCounter pc)
-        # abstract String opcode()
-        # abstract Object[] operands()
-        + abstract String toString()
-    }
+    class Program
     class ArrayList
     class Word {
-        + abstract <T> T getValue()
-        + abstract Word add(Word other)
-        + abstract Word subtract(Word other)
-        + abstract Word multiply(Word other)
-        + abstract Word divide(Word other)
-        + abstract String toString()
-        + abstract boolean equals(Object other)
-    }
-    class Address {
-        - int address
-        + Address(int address)
-        + int getAddress()
-        + String toString()
-    }
-    class LongWord {
-        - Long value
-        + LongWord(Long value)
-        + Long getValue()
+        + <T> T getValue()
         + Word add(Word other)
         + Word subtract(Word other)
         + Word multiply(Word other)
@@ -62,88 +39,49 @@ classDiagram
         + String toString()
         + boolean equals(Object other)
     }
-    class Add {
-        - Address src
-        - Word imm
-        - Address dest
-        + Add(Address src, Word imm, Address dest)
-        + void execute(Memory memory, ProgramCounter PC)
-        + String opcode()
-        + Object[] operands()
+    class Address {
+        - int address
+        + Address(int address)
+        + int getAddress()
         + String toString()
     }
-    class Copy {
-        - Word imm
-        - Address dest
-        + Copy(Word imm, Address dest)
-        + void execute(Memory memory, ProgramCounter PC)
-        + String opcode()
-        + Object[] operands()
-        + String toString()
-    }
-    class Halt {
-        + Halt()
-        + void execute(Memory memory, ProgramCounter PC)
-        + String opcode()
-        + Object[] operands()
-        + String toString()
-    }
-    class Jump {
-        - int index
-        + Jump(int index)
-        + void execute(Memory memory, ProgramCounter PC)
-        + String opcode()
-        + Object[] operands()
-        + String toString()
-    }
-    class JumpEq {
-        - int index
-        - Address src
-        - Word imm
-        + JumpEq(int index, Address src, Word imm)
-        + void execute(Memory memory, ProgramCounter PC)
-        + String opcode()
-        + Object[] operands()
-        + String toString()
-    }
-    class Mul {
-        - Address src1
-        - Address src2
-        - Address dest
-        + Mul(Address src1, Address src2, Address dest)
-        + void execute(Memory memory, ProgramCounter PC)
-        + String opcode()
-        + Object[] operands()
-        + String toString()
-    }
-    class Print {
-        - Address address
-        + Print(Address address)
-        + void execute(Memory memory, ProgramCounter PC)
-        + String opcode()
-        + Object[] operands()
-        + String toString()
-    }
-    Memory <|-- LongMemory
-    Word <|-- LongWord
-    Program <-- ArrayList
-    Program --|> Instruction
-    Program : +toString()
+    class LongMemory
+    class LongWord
     Computer --> Memory
     Computer --> Program
     Computer --> ProgramCounter
-    ProgramCounter --> Program
-    ProgramCounter --> Instruction
-    ProgramCounter : +toString()
-    Instruction : +toString()
-    Instruction <|-- Add
-    Instruction <|-- Copy
-    Instruction <|-- Halt
-    Instruction <|-- Jump
-    Instruction <|-- JumpEq
-    Instruction <|-- Mul
-    Instruction <|-- Print
-    Add --> Address
+    Program <-- ArrayList
+    Program : +toString()
+    Memory <|-- LongMemory
+    Word <|-- LongWord
+
+
+```
+
+```mermaid
+classDiagram
+    class Instruction {
+        + void execute(Memory memory, ProgramCounter pc)
+        # String opcode()
+        # Object[] operands()
+        + String toString()
+    }
+    class Add
+    class Copy
+    class Halt
+    class Jump
+    class JumpEq
+    class Mul
+    class Print
+    Instruction --|> Word
+    Instruction --|> Address
+    Add --|> Instruction
+    Copy --|> Instruction
+    Halt --|> Instruction
+    Jump --|> Instruction
+    JumpEq --|> Instruction
+    Mul --|> Instruction
+    Print --|> Instruction
 ```
 
 ```mermaid