module Main where

import Data.List
import Control.Monad
import Debug.Trace
import qualified Data.ByteString.Char8 as BC
import Data.Maybe (fromJust)
import qualified Data.Set  as S
import qualified Data.IntMap.Strict as IM
import Data.Char


readTuple2 :: IO (Int, Int)
readTuple2 = do
    [a, b] <- map (fst . fromJust . BC.readInt) . BC.words <$> BC.getLine
    return (a, b)

readTuple3 :: IO (Int, Int, Int)
readTuple3 = do
    [a, b, c] <- map (fst . fromJust . BC.readInt) . BC.words <$> BC.getLine
    return (a, b, c)

readInt :: IO Int
readInt = fst . fromJust . BC.readInt <$> BC.getLine

readInts :: IO [Int]
readInts = map (fst . fromJust . BC.readInt) . BC.words <$> BC.getLine

split :: (a -> Bool) -> [a] -> [[a]]
split f [] = []
split f as = let
    (fo, la) = span f as
    las = case la of
        [] -> []
        xs -> split f $ tail xs
    in
        case fo of
            [] -> las
            xs -> xs : las


large = 100000

solve :: [Int] -> [Int] -> [(Int, Int, Int)] -> Int
solve as bs waribikiList = 
    let
        minA = minimum as
        minB = minimum bs
        currentMin = minA + minB
        aMap = IM.fromList $ zip [1..] as
        bMap = IM.fromList $ zip [1..] bs
        getA x = IM.findWithDefault large x aMap
        getB y = IM.findWithDefault large y bMap
        go minim (x, y, c) = min minim $ (getA x + getB y - c)
    in
    foldl' go currentMin waribikiList

main = do
    (a, b, m) <- readTuple3
    as <- readInts
    bs <- readInts
    waribikiList <- replicateM m (readTuple3)
    print $ solve as bs waribikiList


