n, *rest = map(int, open(0).read().split())
A = rest[:n]

max_val = max(A)

if max_val <= 0:
    total = sum(abs(x) for x in A)
else:
    total = 0
    for x in A:
        if x >= 0:
            total += max_val
        else:
            if max_val >= -x:
                total += max_val
            else:
                total += (-x)
print(total)