Negative days completion.

programs/lst35/main.c

@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int main(void) {
+    int n;
+
+    printf("Input integer: ");
+    scanf("%d", &n);
+
+    if (n)
+        puts("The integer is not null(zero).");
+    else
+        puts("The integer is null(zero).");
+
+    return 0;
+}