output_description: If A + B is 10 or greater, print the string `error` (case-sensitive);
  otherwise, print the value of A + B.
  
  * * *
input_description: Input is given from Standard Input in the following format:
  
      
      
      A B
attempt: fn read() -> (i32, i32) {
      let mut s = String::new();
      std::io::stdin().read_line(&mut s).unwrap();
      let vec: Vec<i32> = s
          .trim()
          .split_whitespace()
          .map(|x| x.parse().unwrap())
          .collect();
      (vec[0], vec[1])
  }
  
  fn main() {
      let (a, b) = read();
      if a + b < 10 {
          println!("{}", a + b);
      } else {
          println!("error");
      }
  }
  
problem_description: Statement
  
  You are given two integers A and B as the input. Output the value of A + B.
  
  However, if A + B is 10 or greater, output `error` instead.
samples: [{"input": "6 3", "output": "9\n    \n\n* * *"}, {"input": "6 4", "output": "error"}]