Alaa m ali

#include <iomanip>
#include <iostream>
#include <functional>
#include <algorithm>
#include <math.h>
#include <cmath>
#include <string>

using namespace std;

int main(){
    int n;
    int s = 0, z, x, v = 1000000;
    cin >> n;
    for (int i = 0; i < n; i++){
        cin >> x >> z;
        s = s + z - x;
        if (s < v){
            v = s;
        }
    }
    cout << v;
}