diff --git a/README.md b/README.md
index fbb61b4..609244f 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,14 @@
 # incfunc
 
-Incrementally Draw derivation function of deriviation function of function
\ No newline at end of file
+Incrementally Draw derivation function of deriviation function of function
+
+## Usage
+
+Usage: incfunc [OPTIONS]
+
+Options:
+  -o <OPT_LEVEL>      Optimization level [default: 3]
+  -c <CORES>          Number of cores [default: max]
+      --unsafe-mode   Unsave mode (Advanced)
+  -h, --help          Print help
+
diff --git a/grid_image.png b/grid_image.png
index 79f4b39..68deef5 100644
Binary files a/grid_image.png and b/grid_image.png differ
diff --git a/src/main.rs b/src/main.rs
index b6ea47d..c33c0f2 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -15,7 +15,11 @@ struct Args {
 
     /// Number of cores [default: max]
     #[arg(short, value_name = "CORES")]
-    core: Option<u8>
+    core: Option<u8>,
+
+    /// Unsave mode (Advanced)
+    #[arg(long, default_value_t = false)]
+    unsafe_mode: bool
 }
 
 
@@ -34,6 +38,13 @@ fn main() {
     //     // points.push(-(i as f64 / 10000.0));
     // }
     
+    if args.opt_level > 8 {
+        if ! args.unsafe_mode {
+            panic!("WARNING: This will use at least 30GB RAM\nMake sure you want to use this, then enable save mode");
+        } else {
+            println!("WARNING: This will use at least 30GB RAM\nMake sure you want to use this");
+        }
+    }
     let mut step = "0.".to_string();
     for _ in 0..args.opt_level {
         step.push('0')