int dt1=1;
int dt2=60;
void setup() {
  // put your setup code here, to run once:
  pinMode(13, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  // for(int i1=0;i1<15;i1++){
  //   for(int i=0;i<15;i++){
digitalWrite(13, HIGH);
delayMicroseconds(dt1);
digitalWrite(13, LOW);
delayMicroseconds(dt2);
//}
 // }
}