diff --git a/.drone.yml b/.drone.yml
index c114bb7..d016230 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -5,16 +5,16 @@ name: default
 
 steps:
   - name: hello world
-    image: alpine
+    image: alpine:3.16.2
     commands:
       - echo hello
       - echo world
   - name: python
-    image: python
+    image: python:3.11-rc-alpine
     commands:
       - python3 -c "print(6 * 7)"
   - name: algo2
-    image: gcc
+    image: gcc:12.2.0
     commands:
       - cd algo2
       - gcc -o pairingheap pairingheap.c
diff --git a/algo2/pairingheap.c b/algo2/pairingheap.c
index 4e0e8d0..cff53ee 100644
--- a/algo2/pairingheap.c
+++ b/algo2/pairingheap.c
@@ -166,7 +166,7 @@ int main() {
     struct PHeap ph;
     ph_init(&ph);
 
-    for (int i = 0; i < 20; i++) {
+    for (int i = 0; i < 15; i++) {
         ph_insert_malloc(&ph, rand() % 100);
     }