#include <cstdio>

const int maxm = 100000;

FILE *in = fopen("stergeri.in","r"), *out = fopen("stergeri.out","w");

int n, m, k;

int x[maxm], y[maxm];

int main()
{
    fscanf(in, "%d %d %d", &n, &m, &k);

    for ( int i = 0; i != m; ++i )
        fscanf(in, "%d %d", &x[i], &y[i]);

    for ( int i = m - 1; i >= 0; --i )
        if ( x[i] <= k )
            k += y[i] - x[i] + 1;

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



	return 0;
}