#include <fstream>

using namespace std;

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

#define N 100005
struct interval
{
    long long x, y;
}a[N];
long long n, m, k;

void citire()
{
    fin >> n >> m >> k;
    for(int i = 1; i <= m; i++)
        fin >> a[i].x >> a[i].y;
}
int main()
{
    citire();
    for(int i = m; i >= 1; i--)
    {
        long long lg = a[i].y - a[i].x + 1;
        if(k >= a[i].x)
            k += lg;
    }
    fout << k;
    return 0;
}