Buggy python submission (verdict: Time Limit Exceeded):
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

pos = [[0] * 2 for i in range(N)]
total = 0

if M <= N:
    print(0)
    sys.exit()

for i in range(N):
    pos[i][0] = i
    pos[i][1] = abs(X[i+1] - X[i])
    total = total + pos[i][1]

pos = sorted(pos, key=lambda x:(x[1]))

for j in range(N, M-1):
    dim = abs(X[j+1]-X[j])
    total = total + dim
    if pos[0][1] < dim:
        pos[0][0] = j
        pos[0][1] = dim
        pos = sorted(pos, key=lambda x:(x[1]))


for i in range(1, N):
    total = total - pos[i][1]

print(total)


Fixed submission:
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

L = []

for i in range(1, M):
    L.append(X[i]-X[i-1])

L = sorted(L, reverse=True)

print(X[M-1]-X[0]-sum(L[:N-1]))

Buggy python submission (verdict: Time Limit Exceeded):
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

pos = [[0] * 2 for i in range(N)]
total = 0

if M <= N:
    print(0)
    sys.exit()

for i in range(N):
    pos[i][0] = i
    pos[i][1] = abs(X[i+1] - X[i])
    total = total + pos[i][1]

pos = sorted(pos, key=lambda x:(x[1]))

for j in range(N, M-1):
    dim = abs(X[j+1]-X[j])
    total = total + dim
    if pos[0][1] < dim:
        pos[0][0] = j
        pos[0][1] = dim
        pos = sorted(pos, key=lambda x:(x[1]))


for i in range(1, N):
    total = total - pos[i][1]

print(total)


Fixed submission:
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

L = []

for i in range(1, M):
    L.append(X[i]-X[i-1])

L = sorted(L, reverse=True)

print(X[M-1]-X[0]-sum(L[:N-1]))

Buggy python submission (verdict: Time Limit Exceeded):
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

pos = [[0] * 2 for i in range(N)]
total = 0

if M <= N:
    print(0)
    sys.exit()

for i in range(N):
    pos[i][0] = i
    pos[i][1] = abs(X[i+1] - X[i])
    total = total + pos[i][1]

pos = sorted(pos, key=lambda x:(x[1]))

for j in range(N, M-1):
    dim = abs(X[j+1]-X[j])
    total = total + dim
    if pos[0][1] < dim:
        pos[0][0] = j
        pos[0][1] = dim
        pos = sorted(pos, key=lambda x:(x[1]))



pos = sorted(pos, key=lambda x:(x[1]), reverse = True)
for i in range(N-1):
    total = total - pos[i][1]

print(total)


Fixed submission:
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

L = []

for i in range(1, M):
    L.append(X[i]-X[i-1])

L = sorted(L, reverse=True)

print(X[M-1]-X[0]-sum(L[:N-1]))

Buggy python submission (verdict: Time Limit Exceeded):
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

pos = [[0] * 2 for i in range(N)]
total = 0

if M <= N:
    print(0)
    sys.exit()

for i in range(N):
    pos[i][0] = i
    pos[i][1] = abs(X[i+1] - X[i])
    total = total + pos[i][1]


for j in range(N, M-1):
    dim = abs(X[j+1]-X[j])
    total = total + dim
    pos = sorted(pos, key=lambda x:(x[1]))
    if pos[0][1] < dim:
        pos[0][0] = j
        pos[0][1] = dim



pos = sorted(pos, key=lambda x:(x[1]), reverse = True)
for i in range(N-1):
    total = total - pos[i][1]

print(total)


Fixed submission:
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

L = []

for i in range(1, M):
    L.append(X[i]-X[i-1])

L = sorted(L, reverse=True)

print(X[M-1]-X[0]-sum(L[:N-1]))

Buggy python submission (verdict: Runtime Error):
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

pos = [[0] * 2 for i in range(N)]
total = 0

if N > M:
    print(0)
    sys.exit()

for i in range(N):
    pos[i][0] = i
    pos[i][1] = abs(X[i+1] - X[i])
    total = total + abs(X[i+1] - X[i])


for j in range(N, M-1):
    total = total + abs(X[j+1]-X[j])
    pos = sorted(pos, key=lambda x:(x[1]))
    if pos[0][1] < abs(X[j+1]-X[j]):
        pos[0][0] = j
        pos[0][1] = abs(X[j+1]-X[j])



pos = sorted(pos, key=lambda x:(x[1]), reverse = True)
for i in range(N-1):
    total = total - pos[i][1]

print(total)


Fixed submission:
import sys
N, M = (int(i) for i in input().split())
X = [int(i) for i in input().split()]
X.sort()

L = []

for i in range(1, M):
    L.append(X[i]-X[i-1])

L = sorted(L, reverse=True)

print(X[M-1]-X[0]-sum(L[:N-1]))