#include <cstdio>

using namespace std;

FILE *f, *g;

int n, k, m;

struct numere
{
    int st, dr;
};

numere v[100001];

void readFile()
{
    int i;

    f = fopen("stergeri.in", "r");

    fscanf(f, "%d%d%d", &n, &m, &k);

    for(i = 1; i <= m; i ++)
        fscanf(f, "%d%d", &v[i].st, &v[i].dr);

    fclose(f);
}

void solve()
{
    int i;

    for(i = m; i >= 1; i --)
    {
        if(k >= v[i].st)
            k += (v[i].dr - v[i].st + 1);
    }
}

void printFile()
{
    g = fopen("stergeri.out", "w");

    fprintf(g, "%d\n", k);

    fclose(g);
}

int main()
{
    readFile();

    solve();

    printFile();

    return 0;
}