import Control.Monad
import Data.List
main = getLine >>= main' . map read . words
    where
        main' [n, k]
            | n == 0 && k == 0 = return ()
            | otherwise = replicateM (n + 1) getLine >>= putStrLn . solve . map (map read . words) >> main

solve :: [[Int]] -> String
solve = br . all (>= 0) . foldl1' (zipWith (-))
    where
        br x
            | x = "Yes"
            | otherwise = "No"