Truck Tour1

from collections import deque

gas_station = int(input())
petrol_pumps = deque()

total_petrol = 0
distance_to_next = 0
start_index = 0

for i in range(gas_station):
    petrol, distance = map(int, input().split())
    petrol_pumps.append((petrol, distance))

    total_petrol += petrol
    total_petrol -= distance
    distance_to_next += distance

    if total_petrol < 0:
        start_index = i + 1
        total_petrol = 0
        distance_to_next = 0

print(start_index)