"""
@author : Anidh Singh
This program solves the first assignment in the competitive programming playlist
"""
#designing the lead game solution
valuesList = []
#for adding the new values to the previous values
previous_value_one = 0
previous_value_two = 0
new_list_a=[]
new_list_b=[]
#Inputting all the values to the list
for _ in range(int(input())):
    m, n = map(int, input().split())
    valueOne=m+(previous_value_one)
    #Adding the first value to the list
    valuesList.append(valueOne)
    #Storing the first value which will be used to add later to the 3rd value
    previous_value_one = (valuesList[-1])
    valueTwo=n+(previous_value_two)
    #Adding the second value
    valuesList.append(valueTwo)
    #Storing the second value which will be used to add later to the 4th value
    previous_value_two = (valuesList[-1])