백준 2577

#include <iostream>

using namespace std;

int main() {

    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    int  n, k;
    int sum = 0;
    int big = 0;

    for (int i = 0; i < 10; i++) {
        cin >> n >> k;
        sum += k - n;
        if (sum > big) {
            big = sum;
        }

    }
    cout << big;

    return 0;

}