#include #include #include using namespace std; const int maxn=1000000; bool vis[maxn+5]={1,1}; int pri[80000],cnt,n; typedef long long LL; LL L,R,t; int res; int main() { #ifdef local freopen("pro.in","r",stdin); #endif int m=(int)sqrt(maxn+0.5),c=0,i,j; for(i=2;i<=m;i++) if(!vis[i]) for(j=i*i;j<=maxn;j+=i) vis[j]=1; for(i=2;i<=maxn;i++) if(!vis[i]) pri[cnt++]=i; scanf("%d",&n); while(n-->0) { scanf("%lld%lld",&L,&R); res=0; for(int i=0;i=L) res++; t*=pri[i]; } } printf("%d\n",res); } return 0; }