Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
from heapq import *
def min_cost_flow_dijkstra(E, s, t, f):
    INF = 1<<100
    NN = T + 1
    G = [[] for _ in range(NN)]
    for a, b, cap, c in E:
        G[a].append([b, cap, c, len(G[b])])
        G[b].append([a, 0, -c, len(G[a])-1])
    prevv = [-1] * NN
    preve = [-1] * NN
    h = [0] * NN
    res = 0
    while f > 0:
        dist = [INF] * NN
        dist[s] = 0
        q = []
        heappush(q, (0, s))
        while q:
            di, v = q.pop()
            if dist[v] < di: continue
            for i, (b, _cap, c, r) in enumerate(G[v]):
                if _cap > 0 and dist[b] > dist[v] + c + h[v] - h[b]:
                    dist[b] = dist[v] + c + h[v] - h[b]
                    prevv[b] = v
                    preve[b] = i
                    heappush(q, (dist[b], b))
        
        
        if dist[t] == INF:
            return -1
        for v in range(NN):
            h[v] += dist[v]
        
        d = f
        v = t
        while v != s:
            d = min(d, G[prevv[v]][preve[v]][1])
            v = prevv[v]
        f -= d
        res += d * h[t]
        v = t
        while v != s:
            G[prevv[v]][preve[v]][1] -= d
            G[v][G[prevv[v]][preve[v]][3]][1] += d
            v = prevv[v]
    return res

E = []
inf = 1 << 17
N, H, W = map(int, input().split())
S, T = H+W+N, H+W+N+1
for i in range(H):
    E.append((S, i, 1, 0))
for i in range(W):
    E.append((S, H+i, 1, 0))
for i in range(N):
    r, c, a = map(int, input().split())
    r -= 1
    c -= 1
    E.append((r, H+W+i, 1, 0))
    E.append((H+c, H+W+i, 1, 0))
    E.append((H+W+i, T, 1, inf - a))

E.append((S, T, H+W, inf))
print(inf * (H+W) - min_cost_flow_dijkstra(E, S, T, H+W))

Fixed submission:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] < 0: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) == par(b): return 0
    C[par(a)], C[par(b)] = C[par(a)] + C[par(b)], C[par(a)] + C[par(b)]
    if P[par(b)] == P[par(a)]:
        P[par(b)] = par(a)
        P[par(a)] -= 1
    elif P[par(b)] > P[par(a)]:
        P[par(b)] = par(a)
    else:
        P[par(a)] = par(b)
N, H, W = map(int, input().split())
P = [-1 for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
from heapq import *
def min_cost_flow_dijkstra(E, s, t, f):
    INF = 1<<100
    NN = T + 1
    G = [[] for _ in range(NN)]
    for a, b, cap, c in E:
        G[a].append([b, cap, c, len(G[b])])
        G[b].append([a, 0, -c, len(G[a])-1])
    prevv = [-1] * NN
    preve = [-1] * NN
    h = [0] * NN
    res = 0
    while f > 0:
        dist = [INF] * NN
        dist[s] = 0
        q = []
        heappush(q, (0, s))
        while q:
            di, v = q.pop()
            if dist[v] < di: continue
            for i, (b, _cap, c, r) in enumerate(G[v]):
                if _cap > 0 and dist[b] > dist[v] + c + h[v] - h[b]:
                    dist[b] = dist[v] + c + h[v] - h[b]
                    prevv[b] = v
                    preve[b] = i
                    heappush(q, (dist[b], b))
        
        
        if dist[t] == INF:
            return -1
        for v in range(NN):
            h[v] += dist[v]
        
        d = f
        v = t
        while v != s:
            d = min(d, G[prevv[v]][preve[v]][1])
            v = prevv[v]
        f -= d
        res += d * h[t]
        v = t
        while v != s:
            G[prevv[v]][preve[v]][1] -= d
            G[v][G[prevv[v]][preve[v]][3]][1] += d
            v = prevv[v]
    return res

E = []
inf = 1 << 17
N, H, W = map(int, input().split())
S, T = H+W+N, H+W+N+1
for i in range(H):
    E.append((S, i, 1, 0))
for i in range(W):
    E.append((S, H+i, 1, 0))
for i in range(N):
    r, c, a = map(int, input().split())
    r -= 1
    c -= 1
    E.append((r, H+W+i, 1, 0))
    E.append((H+c, H+W+i, 1, 0))
    E.append((H+W+i, T, 1, inf - a))

E.append((S, T, H+W, inf))
print(inf * (H+W) - min_cost_flow_dijkstra(E, S, T, H+W))

Fixed submission:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] < 0: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) == par(b): return 0
    C[par(a)], C[par(b)] = C[par(a)] + C[par(b)], C[par(a)] + C[par(b)]
    if P[par(b)] == P[par(a)]:
        P[par(b)] = par(a)
        P[par(a)] -= 1
    elif P[par(b)] > P[par(a)]:
        P[par(b)] = par(a)
    else:
        P[par(a)] = par(b)
N, H, W = map(int, input().split())
P = [-1 for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
def min_cost_flow(E, s, t, f):
    INF = 1<<100
    NN = T+1
    G = [[] for _ in range(NN)]
    for a, b, cap, c in E:
        G[a].append([b, cap, c, len(G[b])])
        G[b].append([a, 0, -c, len(G[a])-1])
    prevv = [-1] * NN
    preve = [-1] * NN
    res = 0
    while f > 0:
        dist = [INF] * NN
        dist[s] = 0
        update = 1
        while update:
            update = 0
            for v in range(NN):
                if dist[v] == INF: continue
                for i, (b, _cap, c, r) in enumerate(G[v]):
                    if _cap > 0 and dist[b] > dist[v] + c:
                        dist[b] = dist[v] + c
                        prevv[b] = v
                        preve[b] = i
                        update = 1
        
        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 = t
        while v != s:
            G[prevv[v]][preve[v]][1] -= d
            G[v][G[prevv[v]][preve[v]][3]][1] += d
            v = prevv[v]
    
    return res

E = []
inf = 1 << 17
N, H, W = map(int, input().split())
S, T = H+W+N, H+W+N+1
for i in range(H):
    E.append((S, i, 1, 0))
for i in range(W):
    E.append((S, H+i, 1, 0))
for i in range(N):
    r, c, a = map(int, input().split())
    r -= 1
    c -= 1
    E.append((r, H+W+i, 1, 0))
    E.append((H+c, H+W+i, 1, 0))
    E.append((H+W+i, T, 1, inf - a))

E.append((S, T, H+W, inf))
print(inf * (H+W) - min_cost_flow(E, S, T, H+W))

Fixed submission:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] < 0: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) == par(b): return 0
    C[par(a)], C[par(b)] = C[par(a)] + C[par(b)], C[par(a)] + C[par(b)]
    if P[par(b)] == P[par(a)]:
        P[par(b)] = par(a)
        P[par(a)] -= 1
    elif P[par(b)] > P[par(a)]:
        P[par(b)] = par(a)
    else:
        P[par(a)] = par(b)
N, H, W = map(int, input().split())
P = [-1 for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
def min_cost_flow(E, s, t, f):
    INF = 1<<100
    NN = T+1
    G = [[] for _ in range(NN)]
    for a, b, cap, c in E:
        G[a].append([b, cap, c, len(G[b])])
        G[b].append([a, 0, -c, len(G[a])-1])
    prevv = [-1] * NN
    preve = [-1] * NN
    res = 0
    while f > 0:
        dist = [INF] * NN
        dist[s] = 0
        update = 1
        while update:
            update = 0
            for v in range(NN):
                if dist[v] == INF: continue
                for i, (b, _cap, c, r) in enumerate(G[v]):
                    if _cap > 0 and dist[b] > dist[v] + c:
                        dist[b] = dist[v] + c
                        prevv[b] = v
                        preve[b] = i
                        update = 1
        
        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 = t
        while v != s:
            G[prevv[v]][preve[v]][1] -= d
            G[v][G[prevv[v]][preve[v]][3]][1] += d
            v = prevv[v]
    
    return res

E = []
inf = 1 << 17
N, H, W = map(int, input().split())
S, T = H+W+N, H+W+N+1
for i in range(H):
    E.append((S, i, 1, 0))
for i in range(W):
    E.append((S, H+i, 1, 0))
for i in range(N):
    r, c, a = map(int, input().split())
    r -= 1
    c -= 1
    E.append((r, H+W+i, 1, 0))
    E.append((H+c, H+W+i, 1, 0))
    E.append((H+W+i, T, 1, inf - a))

E.append((S, T, H+W, inf))
print(inf * (H+W) - min_cost_flow(E, S, T, H+W))

Fixed submission:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] < 0: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) == par(b): return 0
    C[par(a)], C[par(b)] = C[par(a)] + C[par(b)], C[par(a)] + C[par(b)]
    if P[par(b)] == P[par(a)]:
        P[par(b)] = par(a)
        P[par(a)] -= 1
    elif P[par(b)] > P[par(a)]:
        P[par(b)] = par(a)
    else:
        P[par(a)] = par(b)
N, H, W = map(int, input().split())
P = [-1 for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] == a: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) != par(b): C[par(a)] += C[par(b)]
    P[par(b)] = par(a)

N, H, W = map(int, input().split())
P = [i for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)


Fixed submission:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] < 0: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) == par(b): return 0
    C[par(a)], C[par(b)] = C[par(a)] + C[par(b)], C[par(a)] + C[par(b)]
    if P[par(b)] == P[par(a)]:
        P[par(b)] = par(a)
        P[par(a)] -= 1
    elif P[par(b)] > P[par(a)]:
        P[par(b)] = par(a)
    else:
        P[par(a)] = par(b)
N, H, W = map(int, input().split())
P = [-1 for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
import sys
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] == a: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) != par(b): C[par(a)] += C[par(b)]
    P[par(b)] = par(a)

N, H, W = map(int, input().split())
P = [i for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)


Fixed submission:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] < 0: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) == par(b): return 0
    C[par(a)], C[par(b)] = C[par(a)] + C[par(b)], C[par(a)] + C[par(b)]
    if P[par(b)] == P[par(a)]:
        P[par(b)] = par(a)
        P[par(a)] -= 1
    elif P[par(b)] > P[par(a)]:
        P[par(b)] = par(a)
    else:
        P[par(a)] = par(b)
N, H, W = map(int, input().split())
P = [-1 for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)

Buggy python submission (verdict: Runtime Error):
def par(a):
    if P[a] == a: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) != par(b): C[par(a)] += C[par(b)]
    P[par(b)] = par(a)

N, H, W = map(int, input().split())
P = [i for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)


Fixed submission:
import sys
input = sys.stdin.readline
sys.setrecursionlimit(10**6)

def par(a):
    if P[a] < 0: return a
    t = par(P[a])
    P[a] = t
    return t
def unite(a, b):
    if par(a) == par(b): return 0
    C[par(a)], C[par(b)] = C[par(a)] + C[par(b)], C[par(a)] + C[par(b)]
    if P[par(b)] == P[par(a)]:
        P[par(b)] = par(a)
        P[par(a)] -= 1
    elif P[par(b)] > P[par(a)]:
        P[par(b)] = par(a)
    else:
        P[par(a)] = par(b)
N, H, W = map(int, input().split())
P = [-1 for i in range(H+W)]
C = [1] * (H+W)
X = []
for _ in range(N):
    r, c, a = map(int, input().split())
    X.append((a, r-1, c+H-1))
X = sorted(X)
ans = 0
while X:
    a, r, c = X.pop()
    unite(r, c)
    if C[par(r)]:
        ans += a
        C[par(r)] -= 1
print(ans)