diff --git a/a4/program.c b/a4/program.c
new file mode 100644
index 0000000..0d3eb75
--- /dev/null
+++ b/a4/program.c
@@ -0,0 +1,61 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+int isMinHeap(int arr[], int len)
+{
+    for (int i = 0; i <= (len - 2) / 2; i++)
+    {
+        int l = 2 * i + 1;
+        int r = 2 * i + 2;
+        if ((l < len && arr[i] > arr[l]) || (r < len && arr[i] > arr[r]))
+        {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+void printPreorder(int arr[], int len, int index, int level)
+{
+    if (index >= len) 
+    {
+        return;
+    }
+
+    for (int i = 0; i < level; i++) 
+    {
+        printf(" ");
+    }
+    printf("%d\n", arr[index]);
+
+    printPreorder(arr, len, 2 * index + 1, level + 1);
+    printPreorder(arr, len, 2 * index + 2, level + 1);
+}
+
+int main()
+{
+    char input[1000];
+    fgets(input, sizeof(input), stdin);
+
+    int kopa[100];
+    int c = 0;
+    char *token = strtok(input, " ");
+    while (token != NULL)
+    {
+        kopa[c++] = atoi(token);
+        token = strtok(NULL, " ");
+    }
+
+    if (isMinHeap(kopa, c))
+    {
+        printf("Je to taka kopa:\n");
+        printPreorder(kopa, c, 0, 0);
+    }
+    else
+    {
+        printf("Nie je kopa.\n");
+    }
+
+    return 0;
+}