human
Examples

Input

4 5 2
0 1 2 1
0 2 1 2
1 2 1 1
1 3 1 3
2 3 2 1

Output

6

Input



Output
Solve the task in PYTHON3.
assistant
#Here is the Python code you requested.

import sys, re
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians, gcd
from itertools import accumulate, permutations, combinations, product, groupby, combinations_with_replacement
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from bisect import bisect, bisect_left
from heapq import heappush, heappop
from functools import reduce
def input(): return sys.stdin.readline().strip()
def INT(): return int(input())
def MAP(): return map(int, input().split())
def LIST(): return list(map(int, input().split()))
def ZIP(n): return zip(*(MAP() for _ in range(n)))
sys.setrecursionlimit(10 ** 9)
INF = float('inf')
mod = 10 ** 9 + 7

class MinCostFlow:
    def __init__(self, n):
        self.n = n
        self.g = [[] for i in range(n)]

    def add_edge(self, fr, to, cap, cost):
        G = self.g
        G[fr].append([to, cap, cost, len(G[to])])
        G[to].append([fr, 0, -cost, len(G[fr])-1])

    def flow(self, s, t, f):
        N = self.n
        G = self.g
        INF = 10**18

        prevv = [0]*N
        preve = [0]*N

        res = 0
        while f > 0:
            dist = [INF]*N
            dist[s] = 0
            update = True

            while update:
                update = False
                for v in range(N):
                    if dist[v] == INF: continue
                    for i in range(len(G[v])):
                        to, cap, cost, rev = G[v][i]
                        if cap > 0 and dist[to] > dist[v]+cost:
                            dist[to] = dist[v]+cost
                            prevv[to] = v
                            preve[to] = i
                            update = True

            if dist[t] == INF:
                return -1

            d = f
            v = t
            while v != s:
                d = min(d, G[prevv[v]][preve[v]][1])
                v = prevv[v]
            f -= d
            res += d*dist[t]

            v =...