Finding the length of connected cells of 1's (regions) in an matrix of 1's and 0's

import java.io.*;

class GFG {
 static int max = 0;
 static int count = 0;
 public static void traverse(int a[][], int r, int c, int i, int j) {
  if (i >= r || j >= c || i < 0 || j < 0) {
   return;
  }
  if (a[i][j] == 0) {
   return;
  } else {
   a[i][j] = 0;
   count++;
   traverse(a, r, c, i - 1, j);
   traverse(a, r, c, i, j - 1);
   traverse(a, r, c, i + 1, j);
   traverse(a, r, c, i, j + 1);
   traverse(a, r, c, i - 1, j - 1);
   traverse(a, r, c, i + 1, j + 1);
   traverse(a, r, c, i - 1, j + 1);
   traverse(a, r, c, i + 1, j - 1);
  }

 }

 public static void main(String[] args) {
  int R = 5;
  int C = 5;
 int a[][] = { { 0, 0, 0, 0, 0},
{ 0, 1, 1, 0, 0},
{ 0, 0, 1, 0, 1},
{ 1, 0, 0, 0, 1},
{ 0, 1, 0, 1, 1}
};


  for (int i = 0; i < R; i++) {
   for (int j = 0; j < C; j++) {
    if (a[i][j] == 1) {
     count = 0;
     traverse(a, R, C, i, j);
     if (count > max) {
      max = count;
     }
    }
   }
  }
  System.out.println("max=" + max);


 }
}