#include<fstream>
using namespace std;
#define Nmax 100010

int N, M, K, A[Nmax], B[Nmax];
int i;

ifstream  f("stergeri.in");
ofstream  g("stergeri.out");

int main()
{
    f >> N >> M >> K;
    for (i=1;i<=M;i++) f >> A[i] >> B[i];
    for (i=M;i>0;i--) K += (B[i]-A[i]+1)*(K>=A[i]);
    g << K;
    return 0;
}