diff --git a/.gitignore b/.gitignore
index cfa9fe2..7a42fe1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,7 @@
 .idea/
+
 output/
+out/
+
 venv
-.venv
\ No newline at end of file
+.venv
diff --git a/zeta_C/completed/2557.c b/zeta_C/completed/2557.c
new file mode 100644
index 0000000..badd63e
--- /dev/null
+++ b/zeta_C/completed/2557.c
@@ -0,0 +1,5 @@
+#include<stdio.h>
+
+int main() {
+    printf("Hello World!");
+}
\ No newline at end of file
diff --git a/zeta_C/stdin.txt b/zeta_C/stdin.txt
new file mode 100644
index 0000000..e69de29