Fix input instruction

src/interpreter.rs

@@ -19,6 +19,8 @@ pub fn run(instructions: &Vec<Instruction>, tape: &mut Vec<u8>, ptr: &mut usize)
         std::io::stdin()
           .read_exact(&mut input)
           .expect("failed to read stdin");
+
+        tape[*ptr] = input[0];
       }
     }
   }

src/main.rs

@@ -10,12 +10,7 @@ fn main() {
     }
     let mut ptr = 512;
 
-    interpreter::run(
-        &parser::parse(lexer::lex("++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++.
-        ")),
-        &mut tape,
-        &mut ptr,
-    )
+    interpreter::run(&parser::parse(lexer::lex(",[>+<-]>.")), &mut tape, &mut ptr)
 }
 
 #[cfg(test)]