#include<fstream>
using namespace std;
int n, m, k, i, j, x[100010], y[100010];
int main(){
    ifstream f("stergeri.in");
    ofstream g("stergeri.out");
    f>>n>>m>>k;
    for(i=1; i<=m; i++)
        f>>x[i]>>y[i];
    f.close();
    for(i=m; i>=1; i--)
        if(x[i]<=k)
            k+=y[i]-x[i]+1;
    g<<k;
    g.close();
    return 0;
}