#include <fstream>

#define MAX 100005

using namespace std;

struct change
{
    int f, l;
}v[MAX];

int main()
{
    int n, m, k;
    ifstream in("stergeri.in"); in>>n>>m>>k;
    for(int i = 1; i <= m; i++)
        in>>v[i].f>>v[i].l;
    in.close();
    while(m)
    {
        if(v[m].f <= k) k += v[m].l - v[m].f + 1;
        m--;
    }
    ofstream out("stergeri.out"); out<<k; out.close();
    return 0;
}