#include <stdio.h>

int N, M, K, X[100005], Y[100005];

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

    scanf("%d %d %d", &N, &M, &K);
    for (i = 1; i <= M; i++)
        scanf("%d %d", &X[i], &Y[i]);

    for (i = M; i; i--)
        if (X[i] <= K)
            K += Y[i]-X[i]+1;

    printf("%d\n", K);

    return 0;
}