116A.cpp

#include <iostream>

using namespace std;

int main()
{
    int number;
    cin >> number;
    int in[number], out[number], i, total=0, minCap=0;

    for(i=0; i<number; i++){
        cin >> out[i] >> in[i];
    }

    for(i=0; i<number; i++){
        total = total + in[i] - out[i];
        if(total > minCap)
            minCap = total;
    }

    cout << minCap;
    return 0;
}