#include <stdio.h>

int s[100003],d[100003];

int main()
{

    FILE*f=fopen("stergeri.in","r");
    int n,m,k;
    fscanf(f,"%d%d%d",&n,&m,&k);

    for(int i=1;i<=m;++i)
        fscanf(f,"%d%d",&s[i],&d[i]);
    fclose(f);

    for(int i=m;i;--i)
    {
        if(s[i]<=k)
            k+=d[i]-s[i]+1;
    }

    FILE*g=fopen("stergeri.out","w");
    fprintf(g,"%d",k);
    fclose(g);

    return 0;
}