#include <cstdio>

#define maxM 100000

using namespace std;

struct interval{
    int x, y;
}v[maxM+5];

int main(){
    freopen("stergeri.in", "r", stdin);
    freopen("stergeri.out", "w", stdout);
    int n, m, k, i;
    scanf("%d%d%d", &n, &m, &k);
    for (i=1; i<=m; i++)
        scanf("%d%d", &v[i].x, &v[i].y);
    for (i=m; i>=1; i--)
        if (k>=v[i].x)
            k+=v[i].y-v[i].x+1;
    printf("%d\n", k);
    return 0;
}