import sequtils,strutils,algorithm

type bound = tuple[a : int,b : int,value : int]
var
    N = stdin.readline.parseInt
    A = newSeqWith(N,newSeq[int](0))
    ans : int
    T : seq[int]
    unit,unit2 : bound
    flag = newSeqWith(N,false)
    Units = newSeq[bound](0)
    flag2 = true
    Max_units = Units
for n in 0..<N:
    A[n] = stdin.readline.split.map(parseInt)

T = @[]
for k in 1..<N:
    for j in 0..<k:
        unit = (k,j,-A[k][j])
        Units.add(unit)
Units = Units.sortedByIt(it.value)


for u in Units:
    if flag[u.a] == false and flag[u.b] == false:
        flag[u.a] = true
        flag[u.b] = true
        Max_units.add((u.a,u.b,-u.value))

while flag2:
    flag2 = false
    for i,u in Max_units:
        for j,u2 in Max_units[0..<i]:
            if A[u.a][u2.b] + A[u.b][u2.a] > u.value + u2.value and A[u.a][u2.b] + A[u.b][u2.a] > A[u.a][u2.a] + A[u.b][u2.b]:
                Max_units[i] = (u.a,u2.b,A[u.a][u2.b])
                Max_units[j] = (u.b,u2.b,A[u.b][u2.a])
                flag2 = true
            elif A[u.a][u2.a] + A[u.b][u2.b] > u.value + u2.value:
                Max_units[i] = (u.a,u2.a,A[u.a][u2.a])
                Max_units[j] = (u.b,u2.b,A[u.b][u2.b])
                flag2 = true
ans = 0
for u in Max_units:
    ans += u.value
echo ans