import sys

# sys.setrecursionlimit(200005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
# inf = (1<<63)-1
inf = (1 << 32)-1
# md = 10**9+7
md = 998244353

class BitSum:
    def __init__(self, n):
        self.n = n+1
        self.table = [0]*self.n

    def add(self, i, x):
        i += 1
        while i < self.n:
            self.table[i] += x
            i += i & -i

    def sum(self, i):
        i += 1
        res = 0
        while i > 0:
            res += self.table[i]
            i -= i & -i
        return res

from heapq import *

n = II()
aa = LI()
lr = LLI(n)

st = set()
alr = []
for a, (l, r) in zip(aa, lr):
    alr.append((a, l, r))
    st.add(a)
    st.add(a+r)
enc = {a: i for i, a in enumerate(sorted(st))}

alr.sort(key=lambda x: -x[0])
hp = []
bit = BitSum(len(enc))
ans = 0
for a, l, r in alr:
    while hp and -hp[0][0] > a:
        _, i = heappop(hp)
        bit.add(i, -1)
    i = enc[a+r]
    ans += bit.sum(i)
    i = enc[a]
    bit.add(i, 1)
    heappush(hp, (-a+l, i))

print(ans)