#include <fstream>
#define N 100000
using namespace std;
ifstream fin("stergeri.in");
ofstream fout("stergeri.out");

int n, m, k;
int x[N], y[N];
int i, j;
int copiek;

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


    for(i=m; i>=1;i--)
        if(x[i]<=k)
           k=k+y[i]-x[i]+1;

    fout << k;
    return 0;
}