import sequtils,strutils
var
    N = stdin.readline.parseInt
    A = newSeq[int](19)
    B = newSeq[int](19)
    dp : array[(1 shl 18), array[20, int]]
    m,nb,ans : int
for i in 0 ..< N:
    (A[i], B[i]) = stdin.readline.split.map(parseInt)
    B[i] -= A[i]
for b in 0 ..< 1 shl N:
    for i in 0 ..< N:
        if (b and (1 shl i)) > 0:
            for j in 0 ..< N:
                if (b and (1 shl j)) == 0:
                    m = max(dp[b][i], B[i] + A[j])
                    nb = (b or (1 shl j))
                    if dp[nb][j] == 0:
                        dp[nb][j] = m
                    else:
                        dp[nb][j] = min(dp[nb][j], m)
echo min(dp[(1 shl N) - 1][0..<N])