Number of Islands

Number of Islands

Given a grid of land and water, count the number of islands.

Input format

The first line contains R and C. The next R lines contain 0/1 values (1 = land).

Output format

Print the number of islands (4-directional connectivity).

Constraints

• Values fit in a 64-bit signed integer
• Trailing whitespace and a trailing newline are ignored by the judge

Read from stdin, write to stdout. Sample cases below show the exact format.

12 2
0 1
1 0
0 0
0 0
1 0
0 1
1 0
1 0
0 0
0 1
0 0
1 1

7

1 11
1 0 1 1 0 1 1 0 0 1 1

4