diff --git a/src/com/jsaasta/froj/Interpreter.java b/src/com/jsaasta/froj/Interpreter.java
index 3534b35..9ccf60f 100644
--- a/src/com/jsaasta/froj/Interpreter.java
+++ b/src/com/jsaasta/froj/Interpreter.java
@@ -1,5 +1,9 @@
 package com.jsaasta.froj;
 
+import com.jsaasta.froj.stdlib.Clock;
+import com.jsaasta.froj.stdlib.Input;
+import com.jsaasta.froj.stdlib.Stdlib;
+
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -12,23 +16,7 @@ public class Interpreter implements Expr.Visitor<Object>, Stmt.Visitor<Void> {
     private Environment environment = globals;
 
     public Interpreter() {
-        globals.define("clock", new FrojCallable() {
-            @Override
-            public int arity() {
-                return 0;
-            }
-
-            @Override
-            public Object call(Interpreter interpreter, List<Object> arguments) {
-                return (double) System.currentTimeMillis() / 1000.0;
-            }
-
-            @Override
-            public String toString() {
-                return "<native fn>";
-            }
-
-        });
+        Stdlib.define().forEach(globals::define);
     }
 
     public void interpret(List<Stmt> statements) {
diff --git a/src/com/jsaasta/froj/stdlib/Clock.java b/src/com/jsaasta/froj/stdlib/Clock.java
new file mode 100644
index 0000000..6029868
--- /dev/null
+++ b/src/com/jsaasta/froj/stdlib/Clock.java
@@ -0,0 +1,25 @@
+package com.jsaasta.froj.stdlib;
+
+import com.jsaasta.froj.FrojCallable;
+import com.jsaasta.froj.Interpreter;
+
+import java.util.List;
+
+public class Clock implements FrojCallable {
+
+    @Override
+    public int arity() {
+        return 0;
+    }
+
+    @Override
+    public Object call(Interpreter interpreter, List<Object> arguments) {
+        return (double) System.currentTimeMillis() / 1000.0;
+    }
+
+    @Override
+    public String toString() {
+        return "<native fn Clock()>";
+    }
+
+}
diff --git a/src/com/jsaasta/froj/stdlib/Input.java b/src/com/jsaasta/froj/stdlib/Input.java
new file mode 100644
index 0000000..42e0616
--- /dev/null
+++ b/src/com/jsaasta/froj/stdlib/Input.java
@@ -0,0 +1,37 @@
+package com.jsaasta.froj.stdlib;
+
+import com.jsaasta.froj.FrojCallable;
+import com.jsaasta.froj.Interpreter;
+import com.jsaasta.froj.RuntimeError;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.List;
+
+public class Input implements FrojCallable {
+
+    @Override
+    public int arity() {
+        return 0;
+    }
+
+    @Override
+    public Object call(Interpreter interpreter, List<Object> arguments) {
+        InputStreamReader input = new InputStreamReader(System.in);
+        BufferedReader reader = new BufferedReader(input);
+        System.out.print("> ");
+        try {
+            String line = reader.readLine();
+            return line;
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Override
+    public String toString() {
+        return "<native fn Clock()>";
+    }
+
+}
diff --git a/src/com/jsaasta/froj/stdlib/Stdlib.java b/src/com/jsaasta/froj/stdlib/Stdlib.java
new file mode 100644
index 0000000..4ce8c58
--- /dev/null
+++ b/src/com/jsaasta/froj/stdlib/Stdlib.java
@@ -0,0 +1,19 @@
+package com.jsaasta.froj.stdlib;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class Stdlib {
+
+    private static final Map<String, Object> classes;
+
+    static {
+        classes = new HashMap<>();
+        classes.put("clock", new Clock());
+        classes.put("input", new Input());
+    }
+
+    public static Map<String, Object> define(){
+        return classes;
+    }
+}