#include <cstdio>
#include <cstdlib>
#include <vector>
using namespace std;

#define nmax 100010

vector<pair<int, int> > V(nmax);
int N, i, K, M;

int main()
{
    freopen("stergeri.in", "r", stdin);
    freopen("stergeri.out", "w", stdout);
    scanf("%i %i %i", &N, &M, &K);
    for(i = 1; i <= M; i++) scanf("%i %i", &V[i].first, &V[i].second);
    for(i = M; i; i--)
        if(V[i].first <= K)
            K += V[i].second - V[i].first + 1;
    printf("%i\n", K);
    return 0;
}