#include <fstream>

using namespace std;

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

int n, m, k, x, y, v[200005], a[200005];

int main()
{
    fin >> n >> m >> k;
    for(int i=1; i<=m; i++)
        fin >> v[i] >> a[i];

    for (int i=m; i>=1; i--)
        if(k>v[i+1])
        k+=a[i]-v[i]+1;

    fout << k;

    return 0;
}