#include <Servo.h>
Servo myservo;  // create servo object to control a servo
int pos;
int po=A0;

void setup() {
  // put your setup code here, to run once:
 myservo.attach(3);
 pinMode(po, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:

  pos =analogRead(po);
  int m= map(pos,0,1023,0,180);
 myservo.write(m); 
}