Buggy python submission (verdict: Time Limit Exceeded):
N=int(input())
line=input()
line=line.rstrip().split(" ")
list1=[]
for i in range(N):
    list1.append(int(line[i])-i-1)
#print(list1)

list2=[]
list3=[]
for j in range(2):
    for k in range(N):
        list2.append(abs(list1[k]-1-j))
        
    list3.append(sum(list2))
    list2=[]
#print(list3)

if list3[0]==list3[1]:
    print(list3[0])
elif list3[0]<list3[1]:
    list2=[]
    list3=[]
    count=100000000000000000
    for l in range(1000000000):
        for m in range(N):
            list2.append(abs(list1[m]-1+l))
        if count>=sum(list2):
            count=sum(list2)
            #print(list2)
            list2=[]
            l=l+10
        else:
            count=100000000000000000
            for n in range(l,l+11):
                for o in range(N):
                    list2.append(abs(list1[o]-1+(n-10)))
                if count>=sum(list2):
                    count=sum(list2)
                    list2=[]
                else:
                    print(count)
                    break
            break        
            
        
else: 
    list2=[]
    list3=[]
    count=100000000000000000
    for l in range(1000000000):
        for m in range(N):
            list2.append(abs(list1[m]-1-l))
        if count>=sum(list2):
            count=sum(list2)
            list2=[]
            l=l+10
        else:
            count=100000000000000000
            for n in range(l,l+11):
                for o in range(N):
                    list2.append(abs(list1[o]-1+(n-10)))
                if count>=sum(list2):
                    count=sum(list2)
                    list2=[]
                else:
                    print(count)
                    break
            break             
        

Fixed submission:
N=int(input())

A=list(map(int,input().split()))

if N==1:
    print(0)
    exit()
elif N==2:
    B=[A[0]-1,A[1]-2]
    b=sum(B)//2
else:
    B=[]
    for i in range(N):
        B.append(A[i]-(1+i))
    #print(B)
    B.sort()
    #print(B)
    b=B[N//2]

ans=0
for i in range(N):
    ans+=abs(A[i]-(b+1+i))
print(ans)

Buggy python submission (verdict: Runtime Error):
line=input()
line=line.rstrip().split(" ")
list1=[]
for i in range(N):
    list1.append(int(line[i])-i-1)
#print(list1)

list2=[]
list3=[]
for j in range(2):
    for k in range(N):
        list2.append(abs(list1[k]-1-j))
        
    list3.append(sum(list2))
    list2=[]
#print(list3)

if list3[0]==list3[1]:
    print(list3[0])
elif list3[0]<list3[1]:
    list2=[]
    list3=[]
    count=100000000000000000
    for l in range(1000000000):
        for m in range(N):
            list2.append(abs(list1[m]-1+l))
        if count>=sum(list2):
            count=sum(list2)
            #print(list2)
            list2=[]
            l=l+10
        else:
            count=100000000000000000
            for n in range(l,l+11):
                for o in range(N):
                    list2.append(abs(list1[o]-1+(n-10)))
                if count>=sum(list2):
                    count=sum(list2)
                    list2=[]
                else:
                    print(count)
                    break
                    
            
        
else: 
    list2=[]
    list3=[]
    count=100000000000000000
    for l in range(1000000000):
        for m in range(N):
            list2.append(abs(list1[m]-1-l))
        if count>=sum(list2):
            count=sum(list2)
            list2=[]
            l=l+10
        else:
            count=100000000000000000
            for n in range(l,l+11):
                for o in range(N):
                    list2.append(abs(list1[o]-1+(n-10)))
                if count>=sum(list2):
                    count=sum(list2)
                    list2=[]
                else:
                    print(count)
                    break
                    
        

Fixed submission:
N=int(input())

A=list(map(int,input().split()))

if N==1:
    print(0)
    exit()
elif N==2:
    B=[A[0]-1,A[1]-2]
    b=sum(B)//2
else:
    B=[]
    for i in range(N):
        B.append(A[i]-(1+i))
    #print(B)
    B.sort()
    #print(B)
    b=B[N//2]

ans=0
for i in range(N):
    ans+=abs(A[i]-(b+1+i))
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
N=int(input())
line=input()
line=line.rstrip().split(" ")
list1=[]
for i in range(N):
    list1.append(int(line[i])-i-1)
#print(list1)

list2=[]
list3=[]
for j in range(2):
    for k in range(N):
        list2.append(abs(list1[k]-1-j))
        
    list3.append(sum(list2))
    list2=[]
#print(list3)

if list3[0]==list3[1]:
    print(list3[0])
elif list3[0]<list3[1]:
    list2=[]
    list3=[]
    count=100000000000000000
    for l in range(1000000000):
        for m in range(N):
            list2.append(abs(list1[m]-1+l))
        if count>=sum(list2):
            count=sum(list2)
            #print(list2)
            list2=[]
        else:
            print(count)
            #print(list2)
            break
        
else: 
    list2=[]
    list3=[]
    count=100000000000000000
    for l in range(1000000000):
        for m in range(N):
            list2.append(abs(list1[m]-1-l))
        if count>=sum(list2):
            count=sum(list2)
            list2=[]
        else:
            print(count)
            #print(list2)
            break
        

Fixed submission:
N=int(input())

A=list(map(int,input().split()))

if N==1:
    print(0)
    exit()
elif N==2:
    B=[A[0]-1,A[1]-2]
    b=sum(B)//2
else:
    B=[]
    for i in range(N):
        B.append(A[i]-(1+i))
    #print(B)
    B.sort()
    #print(B)
    b=B[N//2]

ans=0
for i in range(N):
    ans+=abs(A[i]-(b+1+i))
print(ans)