a = int(input())
x = [int(x) for x in input().split()]
a = len(x) // 2
bullet = 0

if len(x) % 2 != 0:
    
    if sum(x[:a]) > sum(x[a+1:]):
        for i in range (len(x[:a])):
            b = x[:a][i] - x[a+1:][i]
            bullet += b
        
    elif sum(x[a+1:]) > sum(x[:a]):
        for i in range(len(x[a+1:])):
            b = x[a+1:][i] - x[:a][i]
            bullet += b
        
    elif sum(x[a+1:]) > sum(x[:a]):
        bullet += 0
        
else:
    if sum(x[:a]) > sum(x[a:]):
        for i in range (len(x[:a])):
            b = x[:a][i] - x[a:][i]
            bullet += b
        
    elif sum(x[a:]) > sum(x[:a]):
        for i in range(len(x[:a])):
            b = x[a:][i] - x[:a][i]
            bullet += b
    else:
        bullet += 0
    
print(bullet)