Buggy python submission (verdict: Time Limit Exceeded):
import sys
import itertools

n = int(sys.stdin.readline())
MM = [list(map(int, sys.stdin.readline().split())) for _ in range(n)]

amin=1000000000000
for t in itertools.permutations(range(n-1)):
    mm=[m[:] for m in MM]
    o = list(t)
    ans=0
    for _ in range(n-1):
        i = o.pop(0)
        ans += mm[i][0]*mm[i+1][1]*mm[i][1]

        mm[i][1] = mm[i+1][1]
        mm.pop(i+1)
        
        for j in range(len(o)):
            if o[j]>i: o[j] -=1

    if amin>ans: amin=ans


print(amin)


Fixed submission:
import sys

n = int(sys.stdin.readline())

m = list(map(int, sys.stdin.readline().split()))
for _ in range(n-1):
    _, a = sys.stdin.readline().split()
    m.append(int(a))

c = [[-1 for _ in range(n)] for _ in range(n)]

def val(a, b):
    if a==b: return 0
    if c[a][b]>0: return c[a][b]
    c[a][b]=val(a+1,b)+m[a-1]*m[a]*m[b]
    for k in range(a+1, b):
        v=val(a,k)+val(k+1,b)+m[a-1]*m[k]*m[b]
        if c[a][b]>v: c[a][b]=v
    return c[a][b]

print(val(0, n-1))

Buggy python submission (verdict: Runtime Error):
import sys, itertools

n = int(sys.stdin.readline())
MM = [list(map(int, sys.stdin.readline().split())) for _ in range(n)]

amin = 0
m = MM[0][:]
for i in range(n-1):
    amin += m[0]*m[1]*MM[i+1][1]
    m[1]=MM[i+1][1]


for t in itertools.permutations(range(n-1), n-2):

    mm=[m[:] for m in MM]
    o = list(t)
    ans=0
    for _ in range(n-2):
        i = o.pop(0)
        ans += mm[i][0]*mm[i+1][1]*mm[i][1]
        if ans>amin: break
        mm[i][1] = mm[i+1][1]
        mm.pop(i+1)
        
        for j in range(len(o)):
            if o[j]>i: o[j] -=1
    else:
        ans += mm[0][0]*mm[0][1]*mm[1][1]
        if amin>ans: amin=ans


print(amin)


Fixed submission:
import sys

n = int(sys.stdin.readline())

m = list(map(int, sys.stdin.readline().split()))
for _ in range(n-1):
    _, a = sys.stdin.readline().split()
    m.append(int(a))

c = [[-1 for _ in range(n)] for _ in range(n)]

def val(a, b):
    if a==b: return 0
    if c[a][b]>0: return c[a][b]
    c[a][b]=val(a+1,b)+m[a-1]*m[a]*m[b]
    for k in range(a+1, b):
        v=val(a,k)+val(k+1,b)+m[a-1]*m[k]*m[b]
        if c[a][b]>v: c[a][b]=v
    return c[a][b]

print(val(0, n-1))

Buggy python submission (verdict: Runtime Error):
import sys, itertools

n = int(sys.stdin.readline())
MM = [list(map(int, sys.stdin.readline().split())) for _ in range(n)]

amin = 0
m = MM[0][:]
for i in range(n-1):
    amin += m[0]*m[1]*MM[i+1][1]
    m[1]=MM[i+1][1]


for t in itertools.permutations(range(n-1), n-2):

    mm=[m[:] for m in MM]
    o = list(t)
    ans=0
    for _ in range(n-2):
        i = o.pop(0)
        ans += mm[i][0]*mm[i+1][1]*mm[i][1]
        if ans>amin: break
        mm[i][1] = mm[i+1][1]
        mm.pop(i+1)
        
        for j in range(len(o)):
            if o[j]>i: o[j] -=1
    else:
        ans += mm[0][0]*mm[0][1]*mm[1][1]
        if amin>ans: amin=ans


print(amin)


Fixed submission:
import sys

n = int(sys.stdin.readline())

m = list(map(int, sys.stdin.readline().split()))
for _ in range(n-1):
    _, a = sys.stdin.readline().split()
    m.append(int(a))

c = [[-1 for _ in range(n)] for _ in range(n)]

def val(a, b):
    if a==b: return 0
    if c[a][b]>0: return c[a][b]
    c[a][b]=val(a+1,b)+m[a-1]*m[a]*m[b]
    for k in range(a+1, b):
        v=val(a,k)+val(k+1,b)+m[a-1]*m[k]*m[b]
        if c[a][b]>v: c[a][b]=v
    return c[a][b]

print(val(0, n-1))

Buggy python submission (verdict: Time Limit Exceeded):
import sys, itertools

n = int(sys.stdin.readline())
if n==1:
    print(0)
    quit()

MM = [list(map(int, sys.stdin.readline().split())) for _ in range(n)]

amin = 0
m = MM[0][:]
for i in range(n-1):
    amin += m[0]*m[1]*MM[i+1][1]
    m[1]=MM[i+1][1]


for t in itertools.permutations(range(n-1), n-2):

    mm=[m[:] for m in MM]
    o = list(t)
    ans=0
    for _ in range(n-2):
        i = o.pop(0)
        ans += mm[i][0]*mm[i+1][1]*mm[i][1]
        if ans>amin: break
        mm[i][1] = mm[i+1][1]
        mm.pop(i+1)
        
        for j in range(len(o)):
            if o[j]>i: o[j] -=1
    else:
        ans += mm[0][0]*mm[0][1]*mm[1][1]
        if amin>ans: amin=ans


print(amin)


Fixed submission:
import sys

n = int(sys.stdin.readline())

m = list(map(int, sys.stdin.readline().split()))
for _ in range(n-1):
    _, a = sys.stdin.readline().split()
    m.append(int(a))

c = [[-1 for _ in range(n)] for _ in range(n)]

def val(a, b):
    if a==b: return 0
    if c[a][b]>0: return c[a][b]
    c[a][b]=val(a+1,b)+m[a-1]*m[a]*m[b]
    for k in range(a+1, b):
        v=val(a,k)+val(k+1,b)+m[a-1]*m[k]*m[b]
        if c[a][b]>v: c[a][b]=v
    return c[a][b]

print(val(0, n-1))

Buggy python submission (verdict: Time Limit Exceeded):
import sys, copy

num = int(sys.stdin.readline())

if num==1:
    print(0)
    quit()
    
mm = list(map(int, sys.stdin.readline().split()))
for _ in range(num-1):
    mm.append(int(sys.stdin.readline().split()[1]))

used = [False] * num
seq = [0] * (num-2)
minv = 0
j=mm[1]
for i in mm[2:]:
    minv += i*j
    j=i
minv *= mm[0]    

def sequence(n, k, m, t):
    global minv, used, seq
    if k==m:
        t += mm[0]*mm[used[1:].index(False)+1]*mm[num]
        if minv>t:    minv = t
    else:
        for i in range(1,n+1):
            if used[i]: continue
            seq[m] = i
            used[i]=True

            l=i-1
            while l>0 and used[l]:     l-=1
            u=i+1
            while u<num and used[u]:   u+=1
            v = mm[l]*mm[i]*mm[u]
            if minv>t+v: sequence(n, k, m+1, t+v)
            used[i]=False

sequence(num-1, num-2, 0, 0)

print(minv)


Fixed submission:
import sys

n = int(sys.stdin.readline())

m = list(map(int, sys.stdin.readline().split()))
for _ in range(n-1):
    _, a = sys.stdin.readline().split()
    m.append(int(a))

c = [[-1 for _ in range(n)] for _ in range(n)]

def val(a, b):
    if a==b: return 0
    if c[a][b]>0: return c[a][b]
    c[a][b]=val(a+1,b)+m[a-1]*m[a]*m[b]
    for k in range(a+1, b):
        v=val(a,k)+val(k+1,b)+m[a-1]*m[k]*m[b]
        if c[a][b]>v: c[a][b]=v
    return c[a][b]

print(val(0, n-1))