diff --git a/demo/1.in b/demo/1.in
new file mode 100644
index 0000000..216e97c
--- /dev/null
+++ b/demo/1.in
@@ -0,0 +1 @@
+World
diff --git a/demo/demo.py b/demo/demo.py
new file mode 100644
index 0000000..c5f0684
--- /dev/null
+++ b/demo/demo.py
@@ -0,0 +1,27 @@
+import _judger
+import os
+
+if os.system("gcc main.c -o main"):
+    print("compile error")
+    exit(1)
+
+ret = _judger.run(max_cpu_time=1000,
+                  max_real_time=2000,
+                  max_memory=128 * 1024 * 1024,
+                  max_process_number=200,
+                  max_output_size=10000,
+                  max_stack=32 * 1024 * 1024,
+                  # five args above can be _judger.UNLIMITED
+                  exe_path="main",
+                  input_path="1.in",
+                  output_path="/dev/stdout",
+                  error_path="/dev/stderr",
+                  args=[],
+                  # can be empty list
+                  env=[],
+                  log_path="judger.log",
+                  # can be None
+                  seccomp_rule_name="c_cpp",
+                  uid=0,
+                  gid=0)
+print(ret)
diff --git a/demo/main.c b/demo/main.c
new file mode 100644
index 0000000..14bff03
--- /dev/null
+++ b/demo/main.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+    char input[1000];
+    scanf("%s", input);
+    printf("Hello %s\n", input);
+    return 0;
+}
\ No newline at end of file