// 2 leds 1 direction
int pinarr{} {2} = { {2,3}, {3,4}, {4,5}, {5,6}, {6,7}, {7,8}, {8,9}, {9,10}, {10,11}, {11,12}, {12,13} };

void setup() {
  // put your setup code here, to run once:
  for (int c = 2; c < 14; c++) pinMode(c, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  for (auto& b :pinar )
}