#include <stdio.h>
#define M 100002

long n,m,k,i,poz,x[M],y[M];

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