import sys
from math import sqrt, pi, sin
inp = lambda : sys.stdin.readline()[:-1]
mii = lambda x = " ": [*map(int,inp().split(x))]
mfi = lambda x = " ": [*map(float,inp().split(x))]
ii = lambda : int(inp())
def f(n):
d = [i * i for i in range(10, 200, 20)]
for i in range(len(d)):
if n <= d[i]:
return 10 - i
return 0
ans = 0
for i in range(ii()):
a, b = mii()
ans += f(a * a + b * b)
print(ans)