diff --git a/1ano/2semestre/poo/src/tp_codecheck/tp03/TrafficLight1.java b/1ano/2semestre/poo/src/tp_codecheck/tp03/TrafficLight1.java
new file mode 100644
index 0000000..16a2a86
--- /dev/null
+++ b/1ano/2semestre/poo/src/tp_codecheck/tp03/TrafficLight1.java
@@ -0,0 +1,66 @@
+package tp_codecheck.tp03;
+
+/**
+   A simulated traffic light.
+*/
+public class TrafficLight1
+{
+   private String color;
+   private int reds;
+
+   /**
+      Constructs a green traffic light.
+   */
+   public TrafficLight1()
+   {
+      this.color = "green";
+      this.reds = 0;
+   }
+
+   /**
+      Constructs a traffic light.
+      @param initialColor the initial color "green", "yellow", or "red"
+   */
+   public TrafficLight1(String initialColor)
+   {
+      this.color = initialColor;
+      this.reds = initialColor == "red" ? 1 : 0;
+   }
+
+   /**
+      Moves this traffic light to the next color.
+   */
+   public void next()
+   {
+      switch (this.color) {
+         case "red":
+            this.color = "green";
+            break;
+         case "green":
+            this.color = "yellow";
+            break;
+         case "yellow":
+            this.color = "red";
+            this.reds += 1;
+            break;
+      }
+   }
+
+   /**
+      Returns the current color of this traffic light.
+      @return the current color
+   */
+   public String getColor()
+   {
+      return this.color;
+   }
+
+   /**
+      Counts how often this traffic light has been red.
+      @return the number of times this traffic light has been red
+   */
+   public int getReds()
+   {
+      return this.reds;
+   }
+}
\ No newline at end of file
diff --git a/1ano/2semestre/poo/src/tp_codecheck/tp03/TrafficLight2.java b/1ano/2semestre/poo/src/tp_codecheck/tp03/TrafficLight2.java
new file mode 100644
index 0000000..154113d
--- /dev/null
+++ b/1ano/2semestre/poo/src/tp_codecheck/tp03/TrafficLight2.java
@@ -0,0 +1,68 @@
+package tp_codecheck.tp03;
+
+/**
+   A simulated traffic light.
+*/
+public class TrafficLight2
+{
+   private int steps;
+
+   /**
+      Constructs a green traffic light.
+   */
+   public TrafficLight2()
+   {
+      this.steps = 0;
+   }
+
+   /**
+      Constructs a traffic light.
+      @param initialColor the initial color "green", "yellow", or "red"
+   */
+   public TrafficLight2(String initialColor)
+   {
+      switch (initialColor) {
+         case "green":
+            this.steps = 0;
+            break;
+         case "yellow":
+            this.steps = 1;
+            break;
+         case "red":
+            this.steps = 2;
+            break;
+      }
+   }
+
+   /**
+      Moves this traffic light to the next color.
+   */
+   public void next()
+   {
+      steps++;
+   }
+
+   /**
+      Returns the current color of this traffic light.
+      @return the current color
+   */
+   public String getColor()
+   {
+      int rem = (this.steps + 1) % 3;
+      if (rem == 0)
+         return "red";
+      else if (rem == 1)
+         return "green";
+      else
+         return "yellow";
+   }
+
+   /**
+      Counts how often this traffic light has been red.
+      @return the number of times this traffic light has been red
+   */
+   public int getReds()
+   {
+      return (this.steps + 1) / 3;
+   }
+}
\ No newline at end of file