I will take input an integer n and take input in n line separated by space.Every line it contains the value of vector(x,y,z). If the sum of vector is 0 then i will print “YES” and if it’s not then print “NO”.

**Input:**

The first line contains a positive integer *n* (1 ≤ *n* ≤ 100), then follow *n* lines containing three integers each: the *x* *i* coordinate, the *y* *i* coordinate and the *z* *i* coordinate of the force vector, applied to the body ( - 100 ≤ *x* *i* , *y* *i* , *z* *i* ≤ 100).

**Output:**

Print the word “YES” if the body is in equilibrium, or the word “NO” if it is not.

*Examples*

input:

```
3
4 1 7
-2 4 -1
1 -5 -3
```

output:

```
NO
```

input:

```
3
3 -1 7
-5 2 -4
2 -1 -3
```

output:

```
YES
```

Here is my code:

```
n = int(input())
c = 0
for x in range(n):
a = list(map(int,input().split()))
c = c + sum(a)
if c == 0:
print("YES")
else:
print("NO")
```

But i got WRONG ANSWER in test case 81.According to this,

Original problem is here.

I don’t want the solution.Just help me to understand what’s going on?