> #include<stdio.h>
> 
> int main()
> {
>     long int i,j,L,M,count;
>     int Tree[10001];
>     scanf("%d %d",&L,&M);
>     if (L!=0&&M!=0)
>     {
>        for (i=0;i<=L;i++)
>          Tree[i]=1;
>        for (i=0;i<M;i++)
>       {
>         long int Begin,End;
>         scanf("%d %d",&Begin,&End);
>         for (j=Begin;j<=End;j++)
>           Tree[j]=0;
>        }
>        count=0;
>        for (i=0;i<=L;i++)
>           if (Tree[i]==1)
>              count++;
>     printf ("%d\n",count);
>    }
>    }


 integer L (1 <= L < 2000000000)  怎么是Tree[10001]？