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ANT hung a banner for the first programming contest it ever held.

Hyeokjin took an image processing course last semester and wants to put what he learned to use, so he is writing a program that counts how many letters the banner holds.

First he applied a filter that turns every part of the banner that belongs to a letter into 1 and every other part into 0.

Looking only at those values, he decided that whenever cells holding 1 touch each other up, down, left, right, or diagonally, the whole connected blob is one letter. In other words, the neighbors of a cell are the eight cells around it.

Given the values Hyeokjin produced with his filter, print how many letters his program counts.

The first line holds the size of the banner, $M$ and $N$. ($1 \le M, N \le 250$)

Lines 2 through $M+1$ hold the banner data. Each line holds $N$ values of one row, separated by spaces, and every value is 0 or 1.

Print the number of letters counted the way Hyeokjin thinks of them.