print((function (fh)
	local y,n = {},{}
	for i=0,9 do y[tostring(i)]=true end
	for _=1,tonumber(fh:read("*l")) do
		local s=fh:read("*l")
		if s:sub(-1,-1)=="S" then
			for k,_ in pairs(y) do if s:find(k)==nil then y[k]=nil end end
		else
			for i=1,7,2 do n[s:sub(i,i)]=true end
		end
	end
	for k,_ in pairs(n) do y[k]=nil end
	return ({next(y)})[1]
end)(io.stdin))