n = int(input('请输入项数： '))

fenzi = 2#分子
fenmu = 1#分母
l = []
s = 0

for i in range(1,n+1):
a = fenzi
b = fenmu

s += (a/b)
l.append('%s/%s'%(a,b))

fenzi = a+b
fenmu = a

print('+'.join(str(i) for i in l),end = '')
print('=%.2f'%s)