diff --git a/V/04/13/01_ReverseIt.c b/V/04/13/01_ReverseIt.c
new file mode 100644
index 000000000..67ebb10ee
--- /dev/null
+++ b/V/04/13/01_ReverseIt.c
@@ -0,0 +1,18 @@
+#include <stdio.h>
+
+int main()
+{
+        int n, i;
+        scanf("%d", &n);
+        int arr[n];
+
+        for(i = 0; i < n; i++)
+        {
+                scanf("%d", &arr[i]);
+        }
+        for(i = n - 1; i >= 0; i--)
+        {
+                printf("%d\n", arr[i]);
+        }
+}
+
diff --git a/V/04/13/02_ReadTheOdds.c b/V/04/13/02_ReadTheOdds.c
new file mode 100644
index 000000000..6c539f397
--- /dev/null
+++ b/V/04/13/02_ReadTheOdds.c
@@ -0,0 +1,42 @@
+#include <stdio.h>
+
+int main()
+{
+        int n, i, num;
+        scanf("%d", &n);
+        int arr[n];
+
+        if(n % 2 == 0)
+        {
+                for(i = 0; i < n;)
+                {
+                        scanf("%d", &num);
+                        if(num % 2 != 0)
+                        {
+                                arr[i] = num;
+                                i++;
+                        }
+                }
+                for(i = 0; i < n / 2; i++)
+                {
+                        printf("%d\n", arr[i] - arr[(n - i) - 1]);
+                }
+	}
+       	else
+       	{
+                for(i = 0; i < n;)
+                {
+                        scanf("%d", &num);
+                        if(num % 2 != 0)
+                        {
+                                arr[i] = num;
+                                i++;
+                        }
+                }
+                for(i = 0; i <= n / 2 - 1; i++)
+                {
+                        printf("%d\n", arr[i] - arr[(n - i) - 1]);
+                }
+                printf("%d", arr[n / 2]);
+        }
+}		
diff --git a/V/04/13/03_Frequency.c b/V/04/13/03_Frequency.c
new file mode 100644
index 000000000..6c417cc33
--- /dev/null
+++ b/V/04/13/03_Frequency.c
@@ -0,0 +1,28 @@
+#include <stdio.h>
+
+int main()
+{
+	char stc[1000];
+	fgets (stc, 1001, stdin);
+
+	int freq[26] = {0};
+	for(int i = 0; stc[i]; i++)
+	{
+		if(stc[i] >= 'A' && stc[i] <= 'Z')
+		{
+			freq[stc[i] - 'A']++;
+	        }
+		if(stc[i] >= 'a' && stc[i] <= 'z')
+		{
+			freq[stc[i] - 'a']++;
+		}
+	}
+
+	for(int i = 0; i < 26; i++)
+	{
+		if(freq[i] > 0)
+		{
+			printf("%c - %d\n", 'a' + i, freq[i]);	
+		}	
+}
+}
diff --git a/V/04/13/04_ReadAndDivide.c b/V/04/13/04_ReadAndDivide.c
new file mode 100644
index 000000000..7686fcf19
--- /dev/null
+++ b/V/04/13/04_ReadAndDivide.c
@@ -0,0 +1,35 @@
+#include <stdio.h>
+#include <math.h>
+#define n 64
+
+int main()
+{
+	int i, c;
+	float sum = 0, nums[n];
+
+	while(i < n)
+	{
+		while(scanf("%f", &nums) != EOF)
+		{
+			c = i - 1;
+			while(c >= 0)
+			{
+				if(nums[i] == nums[c])
+				{
+					i--;
+					break;
+				}
+				c--;
+			}
+			i++;
+		}
+	}
+	printf("%d", i);
+	c = 0;
+	while(c < i)
+	{
+		sum = sum + fmod(nums[i], i);
+		i++;
+	}
+	printf("%d\n%.3f",i , sum);
+}