const int led_pin1 = 7;
const int switch_pin1 = A1;
const int led_pin2 = 12;
const int switch_pin2 = A2;
const int led_pin3 = 13;
const int switch_pin3 = A3;

void setup() {
  pinMode(led_pin1, OUTPUT);
  pinMode(led_pin2, OUTPUT);
  pinMode(led_pin3, OUTPUT);

}

void loop() {
  int switch_value1 = analogRead(switch_pin1);
  int brightness1 = switch_value1/4;

  digitalWrite(led_pin1, brightness1);

  int switch_value2 = analogRead(switch_pin2);
  int brightness2 = switch_value2/4;

  digitalWrite(led_pin2, brightness2);

  int switch_value3 = analogRead(switch_pin3);
  int brightness3 = switch_value3/4;

  digitalWrite(led_pin3, brightness3);

}