#include <fstream>
using namespace std;
ifstream f("stergeri.in");
ofstream g("stergeri.out");

const int maxn=100005;

long long n, p, k, a[maxn], b[maxn], i;

int main()
{
    f>>n>>p>>k;
    for(i=1; i<=p; ++i) f>>a[i]>>b[i];

    for(i=p; i>=1; --i)
        if(k>=a[i]) k=k+b[i]-a[i]+1;

    g<<k<<"\n";
}