Buggy python submission (verdict: Runtime Error):
N = int(input())
h = list(map(int,input().split()))
if max(h) == min(h):
    ans = h[0]

else:
    same = []
    for i in range(N-1):
        if h[i] == h[i+1]:
            same.append(i)
    
    if len(same) >= 1:
        for k in range (len(same)):
            del h[same[k]]
            for j in range(len(same)):
                same[j] -= 1
    
    N = len(h)

    lmin = [] #極小値のリスト
    lmax = [] #極大値のリスト

    if N >=3:
        if max(h) != min(h):
            for i in range(1,N-1):
                if (h[i] > h[i-1]) and (h[i] > h[i+1]):
                    lmax.append(h[i])
            
            for k in range(1,N-1):
                if (h[k] < h[k-1]) and (h[k] < h[k+1]):
                    lmin.append(h[k])

            if h[0] == h[1]:
                lmax.append(h[j])
                
            if h[j] > h[j -1]:
                lmax.append(h[j])
                  
            if (len(lmax) == 1) :
                ans = max(h)

            else:
                ans = sum(lmax) - sum(lmin)
        else:
            ans = h[0]

    if N == 2:
        ans = max(h)

    if N == 1:
        ans = h[0]

#print(lmax)
#print(lmin)
print(ans)


Fixed submission:
N = int(input())
h = list(map(int,input().split()))
if max(h) == min(h):
    ans = h[0]

else:
    same = []
    for i in range(N-1):
        if h[i] == h[i+1]:
            same.append(i)
    
    if len(same) >= 1:
        for k in range (len(same))[::-1]:
            del h[same[k]]
    
    N = len(h)

    lmin = [] #極小値のリスト
    lmax = [] #極大値のリスト

    if N >=3:
        for i in range(1,N-1):
            if (h[i] > h[i-1]) and (h[i] > h[i+1]):
                lmax.append(h[i])
        
        for k in range(1,N-1):
            if (h[k] < h[k-1]) and (h[k] < h[k+1]):
                lmin.append(h[k])

        if h[0] > h[1]:
            lmax.append(h[0])
            
        if h[N-1] > h[N -2]:
            lmax.append(h[N-1])
                
        if (len(lmax) == 1) :
            ans = max(h)

        else:
            ans = sum(lmax) - sum(lmin)
    
    if N == 2:
        ans = max(h)

    if N == 1:
        ans = h[0]

#print(lmax)
#print(lmin)
print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
h = list(map(int,input().split()))

lmin = [] #極小値のリスト
lmax = [] #極大値のリスト

for i in range(1,N-1):
    if (h[i] >= h[i-1]) and (h[i] > h[i+1]):
        lmax.append(h[i])
    
for k in range(1,N-1):
    if (h[k] <= h[k-1]) and (h[k] < h[k+1]):
        lmin.append(h[k])

if h[0] > h[1]:
    lmax.append(h[0])
if h[N-1] > h[N-2]:
    lmax.append(h[N-1])

ans = sum(lmax) - sum(lmin)

print(ans)


Fixed submission:
N = int(input())
h = list(map(int,input().split()))
if max(h) == min(h):
    ans = h[0]

else:
    same = []
    for i in range(N-1):
        if h[i] == h[i+1]:
            same.append(i)
    
    if len(same) >= 1:
        for k in range (len(same))[::-1]:
            del h[same[k]]
    
    N = len(h)

    lmin = [] #極小値のリスト
    lmax = [] #極大値のリスト

    if N >=3:
        for i in range(1,N-1):
            if (h[i] > h[i-1]) and (h[i] > h[i+1]):
                lmax.append(h[i])
        
        for k in range(1,N-1):
            if (h[k] < h[k-1]) and (h[k] < h[k+1]):
                lmin.append(h[k])

        if h[0] > h[1]:
            lmax.append(h[0])
            
        if h[N-1] > h[N -2]:
            lmax.append(h[N-1])
                
        if (len(lmax) == 1) :
            ans = max(h)

        else:
            ans = sum(lmax) - sum(lmin)
    
    if N == 2:
        ans = max(h)

    if N == 1:
        ans = h[0]

#print(lmax)
#print(lmin)
print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
h = list(map(int,input().split()))

lmin = [] #極小値のリスト
lmax = [] #極大値のリスト

for i in range(i,N-1):
    if (h[i] >= h[i-1]) and (h[i] > h[i+1]):
        lmax.append(h[i])
    
for k in range(i,N-1):
    if (h[i] <= h[i-1]) and (h[i] < h[i+1]):
        lmin.append(h[i])

ans = sum(lmax) - sum(lmin)

print(ans)


Fixed submission:
N = int(input())
h = list(map(int,input().split()))
if max(h) == min(h):
    ans = h[0]

else:
    same = []
    for i in range(N-1):
        if h[i] == h[i+1]:
            same.append(i)
    
    if len(same) >= 1:
        for k in range (len(same))[::-1]:
            del h[same[k]]
    
    N = len(h)

    lmin = [] #極小値のリスト
    lmax = [] #極大値のリスト

    if N >=3:
        for i in range(1,N-1):
            if (h[i] > h[i-1]) and (h[i] > h[i+1]):
                lmax.append(h[i])
        
        for k in range(1,N-1):
            if (h[k] < h[k-1]) and (h[k] < h[k+1]):
                lmin.append(h[k])

        if h[0] > h[1]:
            lmax.append(h[0])
            
        if h[N-1] > h[N -2]:
            lmax.append(h[N-1])
                
        if (len(lmax) == 1) :
            ans = max(h)

        else:
            ans = sum(lmax) - sum(lmin)
    
    if N == 2:
        ans = max(h)

    if N == 1:
        ans = h[0]

#print(lmax)
#print(lmin)
print(ans)

Buggy python submission (verdict: Runtime Error):
N = int(input())
h = list(map(int,input().split()))

lmin = [] #極小値のリスト
lmax = [] #極大値のリスト

for i in range(1,N-1):
    if (h[i] >= h[i-1]) and (h[i] > h[i+1]):
        lmax.append(h[i])
    
for k in range(1,N-1):
    if (h[i] <= h[i-1]) and (h[i] < h[i+1]):
        lmin.append(h[i])

ans = sum(lmax) - sum(lmin

print(ans)


Fixed submission:
N = int(input())
h = list(map(int,input().split()))
if max(h) == min(h):
    ans = h[0]

else:
    same = []
    for i in range(N-1):
        if h[i] == h[i+1]:
            same.append(i)
    
    if len(same) >= 1:
        for k in range (len(same))[::-1]:
            del h[same[k]]
    
    N = len(h)

    lmin = [] #極小値のリスト
    lmax = [] #極大値のリスト

    if N >=3:
        for i in range(1,N-1):
            if (h[i] > h[i-1]) and (h[i] > h[i+1]):
                lmax.append(h[i])
        
        for k in range(1,N-1):
            if (h[k] < h[k-1]) and (h[k] < h[k+1]):
                lmin.append(h[k])

        if h[0] > h[1]:
            lmax.append(h[0])
            
        if h[N-1] > h[N -2]:
            lmax.append(h[N-1])
                
        if (len(lmax) == 1) :
            ans = max(h)

        else:
            ans = sum(lmax) - sum(lmin)
    
    if N == 2:
        ans = max(h)

    if N == 1:
        ans = h[0]

#print(lmax)
#print(lmin)
print(ans)