#include <fstream>

using namespace std;

#define nmax 100000

int a[nmax], b[nmax];
int main() {
    int n, m, k, i;
    ifstream cin("stergeri.in");
    ofstream cout("stergeri.out");
    cin >> n >> m >> k;
    for( i = 0; i < m; i++ )
        cin >> a[i] >> b[i];
    for( i = m - 1; i >= 0; i-- ) {
        if( a[i] <= k )
            k += b[i] - a[i] + 1;
    }
    cout << k;
    return 0;
}