"Make a Custom UIGestureRecognizer in Objective-C" Touches Began Method.

ZLetterGestureRecognizer.m

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
   [super touchesBegan:touches withEvent:event]; 
   self.strokePrecision = 10.0; //A 
   if (touches.count > 1) {
      self.state = UIGestureRecognizerStateFailed; // B
      return;
   }
   self.firstTap = [touches.anyObject locationInView:  self.view.superview]; //C
}