#include <bits/stdc++.h>

using namespace std;

ifstream in("stergeri.in");
ofstream out("stergeri.out");

int n,m,k,st[100005],dr[100005];

int main()
{
    in >> n >> m >> k;
    for (int i = 1; i <= m; i++)
        in >> st[i] >> dr[i];
    for (int i = m; i >= 1; i--)
        if (k >= st[i])
            k += dr[i] - st[i] + 1;
    out << k;
    return 0;
}