A soldier wants to buy *w* bananas in the shop. He has to pay *k* dollars for the first banana, 2*k* dollars for the second one and so on (in other words, he has to pay *i*·*k* dollars for the *i*-th banana). 

He has *n* dollars. How many dollars does he have to borrow from his friend soldier to buy *w* bananas?
The first line contains three positive integers *k*, *n*, *w* (1  ≤  *k*, *w*  ≤  1000, 0 ≤ *n* ≤ 10<sup class="upper-index">9</sup>), the cost of the first banana, initial number of dollars the soldier has and number of bananas he wants.
# Read the number of force vectors
n = int(input())



# Initialize variables to store the sums of force components
sum_x = 0
sum_y = 0
sum_z = 0



# Read and process each force vector
for _ in range(n):
    x, y, z = map(int, input().split())
    sum_x += x
    sum_y += y
    sum_z += z



# Check if the sum of force components is zero
if sum_x == 0 and sum_y == 0 and sum_z == 0:
    print("YES")
else:
    print("NO")