diff --git a/exercises/ex1.cpp b/exercises/ex1.cpp
index 2206958..7639181 100644
--- a/exercises/ex1.cpp
+++ b/exercises/ex1.cpp
@@ -1,5 +1,3 @@
-/* Improve this program using a switch-case. */
-
 #include <iostream>
 using namespace std;
 
@@ -11,38 +9,39 @@ int main()
   cout << "Enter week number(1-7): " << endl;
   cin >> week;
 
-  if (week == 1)
-  {
-    cout << "Monday" << endl;
-  }
-  else if (week == 2)
-  {
-    cout << "Tuesday" << endl;
-  }
-  else if (week == 3)
-  {
-    cout << "Wednesday" << endl;
-  }
-  else if (week == 4)
-  {
-    cout << "Thursday" << endl;
-  }
-  else if (week == 5)
-  {
-    cout << "Friday" << endl;
-  }
-  else if (week == 6)
-  {
+switch (week) {
+case 1:
+   cout << "Monday" << endl;
+   break;
+
+case 2:
+   cout << "Tuesday" << endl;
+   break;
+
+case 3:
+   cout << "Wednesday" << endl;
+   break;
+
+case 4:
+   cout << "Thursday" << endl;
+   break;
+
+case 5:
+   cout << "Friday" << endl;
+   break;
+
+case 6:
     cout << "Saturday" << endl;
-  }
-  else if (week == 7)
-  {
+   break;
+
+case 7:
     cout << "Sunday" << endl;
-  }
-  else
-  {
-    cout << "Invalid input! Please enter week number between 1-7." << endl;
-  }
+   break;
+
+default:
+   cout << "Invalid input! Please enter week number between 1-7." << endl;
+   break;
+}
 
   return 0;
 }
\ No newline at end of file
diff --git a/exercises/sum.c b/exercises/sum.c
new file mode 100644
index 0000000..98bc6fe
--- /dev/null
+++ b/exercises/sum.c
@@ -0,0 +1,24 @@
+/*
+  Write a program that takes as input two numbers and print the sum.
+
+  Output:
+  Insert the first number: 1
+  Insert the second number: 2
+  Sum: 3
+*/
+
+#include <stdio.h>
+int x;
+int y;
+int sum;
+
+int main()
+{
+printf("Inserisci il primo numero da sommare: ");
+scanf("%d", &x);
+
+printf("Inserisci il secondo numero da sommare: ");
+scanf("%d", &y);
+
+printf("La somma di %d e %d è %d.\n", x,y, x+y);
+}
\ No newline at end of file
diff --git a/exercises/sum.cpp b/exercises/sum.cpp
deleted file mode 100644
index 0dcca93..0000000
--- a/exercises/sum.cpp
+++ /dev/null
@@ -1,8 +0,0 @@
-/*
-  Write a program that takes as input two numbers and print the sum.
-
-  Output:
-  Insert the first number: 1
-  Insert the second number: 2
-  Sum: 3
-*/