Buggy python submission (verdict: Time Limit Exceeded):
n,m=map(int,input().split())
x=input().split()
for i in range(m):
    a=int(x[i])
    x[i]=a
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    goukei=0
    l=[0]
    i=0
    x.sort()
    a=0
    b=0
    if m>1:
        while i<m-1:
            a=x[i]
            b=x[i+1]
            goukei+=b-a
            l.append(b-a)
            i+=1
    i=0
    l.sort()
    while i<n-1:
        a=max(l)
        goukei-=a
        l.remove(a)
        i+=1
        if l==[]:
            break
    print(goukei)

Fixed submission:
n,m=map(int,input().split())
x=list(map(int,input().split()))
x.sort()
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    x.sort()
    goukei=0
    l=[0]
    for i in range(m-1):
        goukei+=x[i+1]-x[i]
        l.append(x[i+1]-x[i])
    i=0
    l.sort()
    for i in range(n-1):
        goukei-=l[-1-i]
    print(goukei)

Buggy python submission (verdict: Time Limit Exceeded):
n,m=map(int,input().split())
x=list(map(int,input().split()))
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    goukei=0
    l=[0]
    i=0
    x.sort()
    a=0
    b=0
    if m>1:
        while i<m-1:
            a=x[i]
            b=x[i+1]
            goukei+=b-a
            l.append(b-a)
            i+=1
    i=0
    l.sort()
    while i<n-1:
        a=max(l)
        goukei-=a
        l.remove(a)
        i+=1
        if l==[]:
            break
    print(goukei)

Fixed submission:
n,m=map(int,input().split())
x=list(map(int,input().split()))
x.sort()
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    x.sort()
    goukei=0
    l=[0]
    for i in range(m-1):
        goukei+=x[i+1]-x[i]
        l.append(x[i+1]-x[i])
    i=0
    l.sort()
    for i in range(n-1):
        goukei-=l[-1-i]
    print(goukei)

Buggy python submission (verdict: Time Limit Exceeded):
n,m=map(int,input().split())
x=list(map(int,input().split()))
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    goukei=0
    l=[0]
    i=0
    x.sort()
    a=0
    b=0
    while i<m-1:
        a=x[i]
        b=x[i+1]
        goukei+=b-a
        l.append(b-a)
        i+=1
    for v in range(n-1):
        goukei-=max(l)
        l.remove(max(l))
    print(goukei)

Fixed submission:
n,m=map(int,input().split())
x=list(map(int,input().split()))
x.sort()
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    x.sort()
    goukei=0
    l=[0]
    for i in range(m-1):
        goukei+=x[i+1]-x[i]
        l.append(x[i+1]-x[i])
    i=0
    l.sort()
    for i in range(n-1):
        goukei-=l[-1-i]
    print(goukei)

Buggy python submission (verdict: Time Limit Exceeded):
n,m=map(int,input().split())
x=list(map(int,input().split()))
x.sort()
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    goukei=0
    l=[0]
    i=0
    while i<m-1:
        goukei+=x[i+1]-x[i]
        l.append(x[i+1]-x[i])
        i+=1
    i=0
    while i<n-1:
        goukei-=max(l)
        l.remove(max(l))
        i+=1
    print(goukei)

Fixed submission:
n,m=map(int,input().split())
x=list(map(int,input().split()))
x.sort()
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    x.sort()
    goukei=0
    l=[0]
    for i in range(m-1):
        goukei+=x[i+1]-x[i]
        l.append(x[i+1]-x[i])
    i=0
    l.sort()
    for i in range(n-1):
        goukei-=l[-1-i]
    print(goukei)

Buggy python submission (verdict: Time Limit Exceeded):
n,m=map(int,input().split())
x=list(map(int,input().split()))
x.sort()
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    x.sort()
    goukei=0
    l=[0]
    for i in range(m-1):
        goukei+=x[i+1]-x[i]
        l.append(x[i+1]-x[i])
    i=0
    for i in range(n-1):
        goukei-=max(l)
        l.remove(max(l))
    print(goukei)

Fixed submission:
n,m=map(int,input().split())
x=list(map(int,input().split()))
x.sort()
if n==1:
    print(max(x)-min(x))
elif m==1 or n>=m:
    print(0)
else:
    x.sort()
    goukei=0
    l=[0]
    for i in range(m-1):
        goukei+=x[i+1]-x[i]
        l.append(x[i+1]-x[i])
    i=0
    l.sort()
    for i in range(n-1):
        goukei-=l[-1-i]
    print(goukei)