BEGIN {
	FS = "[ ,>-]+";
}
{
	x = $1;
	y = $2;
	for (i = 3; i <= NF; i += 2) {
		tx = $i;
		ty = $(i+1);
		while (x != tx) {
			m[x,y] = "#";
			if (x < tx) x++;
			if (x > tx) x--;
		}
		while (y != ty) {
			m[x,y] = "#";
			if (y < ty) y++;
			if (y > ty) y--;
		}
		m[x,y] = "#";
		if (y > ymax) ymax = y;
	}
}
END {
	x = 500;
	y = 0;
	while (y < ymax) {
		if (!m[x,y+1]) {
			y++;
		} else if (!m[x-1,y+1]) {
			x--;
			y++;
		} else if (!m[x+1,y+1]) {
			x++;
			y++;
		} else {
			m[x,y] = "o";
			sand++;
			x = 500;
			y = 0;
		}
	}
	print sand;
}