import sys
import bisect


class BIT:
    def __init__(self, node_size):
        self._node = node_size+1
        self.bit = [0]*self._node

    def add(self, index, add_val):
        while index < self._node:
            self.bit[index] += add_val
            index += index & -index

    def sum(self, index):
        res = 0
        while index > 0:
            res += self.bit[index]
            index -= index & -index
        return res


if __name__ == '__main__':
    n = int(sys.stdin.readline())
    a = tuple(map(int, sys.stdin.readline().split()))
    l, r = [0]*n, [0]*n
    vec = [None]*(2*n)
    for i in range(n):
        l[i], r[i] = map(int, sys.stdin.readline().split())
        vec[i], vec[n+i] = (a[i], n+i), (a[i]-l[i], i)
    vec.sort()
    bt = BIT(n)
    ans = 0
    for i in range(2*n):
        q = vec[i][1]
        if q >= n:
            q -= n
            ans += bt.sum(bisect.bisect_right(a, a[q]+r[q])) - bt.sum(q+1)
        else:
            bt.add(q+1, 1)
    print(ans)