String inputString = "";

  while (Serial.available()) {
    char inChar = (char)Serial.read();
    inputString += inChar;

    if (inChar == '\n') {
       if(inputString.indexOf("10") >-1 )
          // etc etc
       if(inputString.indexOf("11") >-1 )
          // etc etc
       if(inputString.indexOf("12") >-1 )
          // etc etc

       Serial.println(inputString);
       inputString = "";
    }
  }