A guy named Vasya attends the final grade of a high school. One day Vasya decided to watch a match of his favorite hockey team. And, as the boy loves hockey very much, even more than physics, he forgot to do the homework. Specifically, he forgot to complete his physics tasks. Next day the teacher got very angry at Vasya and decided to teach him a lesson. He gave the lazy student a seemingly easy task: You are given an idle body in space and the forces that affect it. The body can be considered as a material point with coordinates (0; 0; 0). Vasya had only to answer whether it is in equilibrium. "Piece of cake" — thought Vasya, we need only to check if the sum of all vectors is equal to 0. So, Vasya began to solve the problem. But later it turned out that there can be lots and lots of these forces, and Vasya can not cope without your help. Help him. Write a program that determines whether a body is idle or is moving by the given vectors of forces.

Input

The first line contains a positive integer n (1 ≤ n ≤ 100), then follow n lines containing three integers each: the xi coordinate, the yi coordinate and the zi coordinate of the force vector, applied to the body ( - 100 ≤ xi, yi, zi ≤ 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
'''A guy named Vasya attends the final grade 
of a high school. One day Vasya decided to watch 
a match of his favorite hockey team. And, as the 
boy loves hockey very much, even more than physics, 
he forgot to do the homework. Specifically, he forgot 
to complete his physics tasks. Next day the teacher 
got very angry at Vasya and decided to teach him a lesson. 
He gave the lazy student a seemingly easy task: You are 
given an idle body in space and the forces that affect it. 
The body can be considered as a material point with 
coordinates (0; 0; 0). Vasya had only to answer whether 
it is in equilibrium. "Piece of cake" — thought Vasya, 
we need only to check if the sum of all vectors is equal 
to 0. So, Vasya began to solve the problem. But later it 
turned out that there can be lots and lots of these forces, 
and Vasya can not cope without your help. Help him. Write a 
program that determines whether a body is idle or is moving 
by the given vectors of forces.

Input
The first line contains a positive integer n (1 ≤ n ≤ 100), 
then follow n lines containing three integers each: the xi 
coordinate, the yi coordinate and the zi coordinate of the 
force vector, applied to the body ( - 100 ≤ xi, yi, zi ≤ 100).

Output
Print the word "YES" if the body is in equilibrium, 
or the word "NO" if it is not.
'''


ORIGIN_ = [0, 0, 0]


def vector_add( v1, v2 ):
    '''Adds two vectors together elemnt-wise
    IN:
        v1: first vector
        v2: second vector
    OUT:
        v1: the vector resulting of the addition

    '''
    assert len(v1) == len(v2), 'Vectors must have same length'

    for ii, el in enumerate(v2):
        v1[ii] += el
    
    return v1 


def main():
    # retreive number of vectors
    numvec = int( input() )

    #initialize the position of the object to origin
    # need to make deep copy because otherwise operation
    # mutate ORIGIN_ list also.
    coord_ = ORIGIN_.copy()

    # iterate through the n vectors of force and move
    # the object around
    for _ in range( numvec ):
        coord_ = vector_add( coord_,
                            [int(x) for x in 
                            input().split(' ')]
                            )
    
    if coord_ == ORIGIN_ :
        print( 'YES' )
    else:
        print( 'NO' )
    
    return coord_

if __name__ == "__main__": main()
'''
12
3 -1 7
-5 2 -4
2 -1 -3
3 -1 7
-5 2 -4
2 -1 -3
3 -1 7
-5 2 -4
2 -1 -3
3 -1 7
-5 2 -4
2 -1 -3
'''