led matrix multiplex

int gnd[5] = {2, 3, 4, 5, 6,};
int led[7] = {7, 8, 9, 10, 11, 12, 13, };

int x =0;
int y=0;

int mtx [5] [7] = {
  {1, 0, 1, 0, 1, 0, 1,},
  {0, 1, 0, 1, 0, 1, 0,},
  {1, 0, 1, 0, 1, 0, 1,},
  {0, 1, 0, 1, 0, 1, 0,},
  {1, 0, 1, 0, 1, 0, 1,}
};

void setup() {
    for(x=0; x<5;x++){
    pinMode(gnd[x], OUTPUT);
  }

  for(y=0; y<7;y++){
    pinMode(led[x], OUTPUT);
  }
}

void loop() {

 for(x=0;x<5;++x) {
  for(y=0;y<7;++y) digitalWrite(led[y], mtx[x][y]);
  digitalWrite(gnd[x], LOW);
  delay(20);
  digitalWrite(gnd[x], HIGH);
    }
}