diff --git a/Lab3/README.md b/Lab3/README.md
new file mode 100644
index 0000000..d0ca35f
--- /dev/null
+++ b/Lab3/README.md
@@ -0,0 +1,15 @@
+# CCIoT Homework Lab 3
+
+## Slide 6
+
+### Problem
+
+Try this out:
+
+1. Make a vector of pairs (ints);
+2. Sort the vector by the first element in the pair;
+3. Replace the odd pairs with zero on the second element;
+
+### Solution
+
+See [slide6.cpp](./slide6.cpp).
diff --git a/Lab3/slide6.cpp b/Lab3/slide6.cpp
new file mode 100644
index 0000000..b544937
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+++ b/Lab3/slide6.cpp
@@ -0,0 +1,34 @@
+#include <iostream>
+#include <vector>
+#include <utility>
+#include <algorithm>
+
+int main() {
+	// 1.
+	std::vector<std::pair<int, int>> v {{2, 8}, {9, 6}, {4, 7}, {22, 4}, {123, 321}, {1, 1}, {-7, 5}};
+
+	// 2.
+	std::sort(std::begin(v), std::end(v), [](const auto& e1, const auto& e2) {
+		return e1.first < e2.first;
+	});
+
+	// 3.
+	bool odd {true};
+	for (auto it {std::begin(v)}; it != std::end(v); ++it) {
+		if (odd) {
+			(*it).second = 0;
+		}
+		odd = !odd;
+	}
+
+	// Print the results
+	bool first {true};
+	for (const auto& item : v) {
+		if (first) first = false;
+		else std::cout << ", ";
+		std::cout << "(" << item.first << ", " << item.second << ")";
+	}
+	std::cout << std::endl;
+
+	return 0;
+}
\ No newline at end of file
diff --git a/README.md b/README.md
index 5e7ae03..99fe4c0 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,4 @@
 
 - [Lab1](./Lab1/)
 - [Lab2](./Lab2/)
+- [Lab3](./Lab3/)