```
public class Solution {
public int islandPerimeter(int[][] grid) {
if(grid == null || grid.length == 0|| grid[0].length == 0)
return 0;
int perimeter = 0;
int n = grid.length;
int m = grid[0].length;
for(int i = 0; i < n; i++) {
for(int j = 0; j < m; j++) {
if(grid[i][j] == 1) {
if(i == 0 || grid[i - 1][j] == 0)
perimeter++;
if(i == n -1 || grid[i + 1][j] == 0)
perimeter++;
if(j == 0 || grid[i][j - 1] == 0)
perimeter++;
if(j == m - 1|| grid[i][j + 1] == 0)
perimeter ++;
}
}
}
return perimeter;
}
}
```