#include<stdio.h>
FILE *f=fopen("stergeri.in","r"), *g=fopen("stergeri.out","w");

long int N, M, K, i;

struct taie{
    long int x, y;
}v[100010];

int main(){

    fscanf(f,"%ld %ld %ld\n",&N,&M,&K);
    for(i=1;i<=M;i++){  fscanf(f,"%ld %ld\n",&v[i].x,&v[i].y);  }

    for(i=M;i>=1;i--){
        if(v[i].x<=K){ K=K+ v[i].y-v[i].x+1; }
    }
    fprintf(g,"%ld\n",K);

return 0;
}