#include <iostream>
#include <cstdio>

using namespace std;

#define DIM 100005

struct interval {
    int x, y;
} V[DIM];

int main() {
    freopen("stergeri.in","r",stdin);
    freopen("stergeri.out","w",stdout);

    int N, M, K;
    scanf("%d %d %d\n", &N, &M, &K);

    for(int i = 1; i <= M; ++i) {
        scanf("%d %d\n", &V[i].x, &V[i].y);
    }

    for(int i = M; i > 0; --i) {
        if(K >= V[i].x) {
            K += V[i].y - V[i].x + 1;
        }
    }

    cout << K << '\n';

    return 0;
}