N = int(input())                                                                                                                                             
A = list(map(int,input().split()))                                                                                                                           
                                                                                                                                                             
zc = 0                                                                                                                                                       
mc = 0                                                                                                                                                       
abs_min = float('inf')                                                                                                                                       
                                                                                                                                                             
sum_abs = 0                                                                                                                                                  
for a in A:                                                                                                                                                  
    if a == 0:                                                                                                                                               
        zc += 1                                                                                                                                              
    elif a <  0:                                                                                                                                             
        mc += 1                                                                                                                                              
                                                                                                                                                             
    if abs(a) < abs_min:                                                                                                                                     
        abs_min = abs(a)                                                                                                                                     
                                                                                                                                                             
    sum_abs += abs(a)                                                                                                                                        
                                                                                                                                                             
                                                                                                                                                             
if zc > 0 or mc % 2 == 0:                                                                                                                                    
    print(sum_abs)                                                                                                                                           
else:                                                                                                                                                        
    print(sum_abs-abs_min*2)  

Measured memory_bytes: 14224