#include <stdio.h>

#define MAX_M 100005
#define FIN "stergeri.in"
#define FOUT "stergeri.out"

int N, M, K, A[MAX_M], B[MAX_M];

int main(void)
{
    int i;

    freopen(FIN, "r", stdin);
    freopen(FOUT, "w", stdout);

    scanf("%d %d %d", &N, &M, &K);
    for (i = 0; i < M; ++i)
        scanf("%d %d", A+i, B+i);

    for (i = M-1; i >= 0; --i)
        if (K >= A[i]) K += B[i]-A[i]+1;
    printf("%d\n", K);

    return 0;
}