def main():
    n = int(input('Digite o ultimo denominador da sequencia: '))
    s = 0

    for i in range(1,n+1):      
        if(i%2 == 0):
            s -= 1/i
            if(i==n):
                print(f'1/{i} = ', end='')
            else:
                print(f'1/{i} + ', end='')
        else:
            s += 1/i
            if(i==n):
                print(f'1/{i} = ', end='')
            else:
                print(f'1/{i} - ', end='')
    print(f'{s:.2f}')

main()