int servo1degree, servo2degree;
String str_d;

void Receive_serial_data(){  
  while (Serial.available()){    
    char d = (char) Serial.read();
    str_d += d;
    if(d == '\n') {      
      Parse_the_data(str_d);
      str_d = "";            
      break;
    }    
  }  
}

void Parse_the_data(String &theString)
{
  int indexOfA = theString.indexOf("A");
  int indexOfB = theString.indexOf("B");

  if(indexOfA >-1){ 
    String subStr = theString.substring(indexOfA+1);          
    servo1degree = subStr.toInt();   
    Serial.print("Servo1: ");
    Serial.println(servo1degree);
  }

  if(indexOfB >-1){ 
    String subStr = theString.substring(indexOfB+1);              
    servo2degree = subStr.toInt();
    Serial.print("Servo2: ");
    Serial.println(servo2degree);
  }

}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial.println("START");
}

void loop() {
  Receive_serial_data();
}