30394번: 회전하지 않는 캘리퍼스 ↗

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())


n = ii()
l = [mii()[1] for _ in range(n)]

print(max(l) - min(l))