#include <fstream>
using namespace std;ifstream f("stergeri.in"); ofstream g("stergeri.out"); int x[100005], y[100005], n, m, k, i;int main(){f>>n>>m>>k;for (i=1; i<=m; i++) f>>x[i]>>y[i];for (i=m; i; i--) if (x[i]<=k) k+=(y[i]-x[i]+1);g<<k;}