---
# System prepended metadata

title: Dec 17

---

# Dec 17
### Bài 4
```python=
n = int(input())
s = 0
for i in range(1,n+1):
    s+=1/i
print(format(s,'.3f'))
```

### Bài 5
```python=
n = int(input())
s = 0
for i in range(1,n+1):
    s+=1/2*i
print(format(s,'.5f'))
```
### Bài 7
```python=
t = int(input())
for j in range(t):
    n = int(input())
    s=1
    for i in range(2,n+1):
        s*=i
    print(s)

# 6!= 1*2*3*4*5*6
# n!= 1*2*3*..*n
```

```python=
input().split()
#1 2 3 4 
#[1,2,3,4]
input().split('+')
#1+2+3+4
#[1,2,3,4]

```
