const int ledPin = 7;
const int buttonPin = 3;
int s = 10; // 0.3 second delay for 'S' letter
int o = 75; // 1.5 second delay for 'O' letter
int pause = 20; // 0.4 second delay between letters
int buttonState = 0;

void setup() {
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT);
}
void character(int speed, int pause) {
  for (int i = 1; i <= 3; i++) {
    if (digitalRead(buttonPin) == LOW) {
      digitalWrite(ledPin, HIGH);
      delay(speed);
      digitalWrite(ledPin, LOW);
      delay(20);
    }
    else {
      digitalWrite(ledPin, HIGH);
    }
    delay(pause); //delay between letters
  }
}
void loop() {
  character(s, pause);
  character(o, pause);
  character(s, pause);
  delay(200); //delay after each SOS
}