Eradicate Aliens

You are given an island divided into n regions. In each region, there are two types of aliens: Lycans and Vamps. Eradicating each alien takes exactly 1 day. Your task is to compute the total number of days required to eradicate all aliens from the island.

Formally, if the number of Lycans and Vamps in the i-th region are denoted by \(L_i\) and \(V_i\) respectively, then the total number of days required is:

\(total = \sum_{i=1}^{n} (L_i + V_i)\)

Read the input from standard input and output the result to standard output.

inputFormat

The first line contains a single integer n (\(1 \leq n \leq 10^5\)), representing the number of regions.

Each of the following n lines contains two space-separated integers \(L\) and \(V\) (\(0 \leq L, V \leq 10^4\)), representing the number of Lycans and Vamps in that region respectively.

outputFormat

Output a single integer representing the total number of days required to eradicate all aliens from the island.

3
0 0
0 0
0 0

0