nyoj-51

#include<stdio.h>int v[10010];int main(){int L,i,m,t,from,to,sum;//freopen("d:\\test.txt","r",stdin);scanf("%d",&t);while(t--){scanf("%d%d",&L,&m);for(i=0;i<=L;++i)v[i]=0;sum=L+1;for(i=0;i<m;++i){scanf("%d%d",&from,&to);for(int j=from;j<=to;++j)if(!v[j]){v[j]=1;sum--;}}printf("%d\n",sum);}return 0;}