#include<bits/stdc++.h>
using namespace std;
int m[80000],kk=0,h,a,b;
int main()
{
for(int i=2;i<=1000000;i++)
{
int f=0;
for(int j=2;j*j<=i;j++)
if(i%j==0)
{
f=1;
break;
}
if(f==0)
{
kk++;
m[kk]=i;
}
}
int k,u=0;
cin>>k;
while(u<k)
{
u++;
scanf("%d%d",&a,&b);
h=1;
while(m[h]<a&&h<=kk)
{
if(m[h+1000]<a&&h+1000<=kk)h+=1000;
else h++;
}
int hh=h;
h=1;
while(m[h]<b&&h<=kk)
{
if(m[h+1000]<b&&h+1000<=kk)h+=1000;
else h++;
}
if(m[h]!=b)h--;
if(h<hh||h==hh)
{
if(h<hh)cout<<0<<endl;
else cout<<1<<endl;
continue;
}
cout<<h-hh+1<<endl;
}
return 0;
}
//兄弟们也是终于做出来了，及得点个赞

#include <iostream>
using namespace std;

int ackermann(int m, int n) {
if (m == 0) {
return n + 1;
} else if (n == 0) {
return ackermann(m - 1, 1);
} else {
return ackermann(m - 1, ackermann(m, n - 1));
}
}

int main() {
int m, n;
cin >> m >> n;
cout << ackermann(m, n);
return 0;
}//一定对，不对我倒立

#include<bits/stdc++.h>
using namespace std;
int m[80000],kk=0,h,a,b;
int main()
{
    for(int i=2;i<=1000000;i++)
    {
        int f=0;
        for(int j=2;j*j<=i;j++)
            if(i%j==0)
            {
                f=1;
                break;
                }
                    if(f==0)
                {
                    kk++;
                    m[kk]=i;
                }
                }
                    int k,u=0;
                    cin>>k;
                    while(u<k)
                {
                    u++;
                    scanf("%d%d",&a,&b);
                    h=1;
                    while(m[h]<a&&h<=kk)
                {
                    if(m[h+1000]<a&&h+1000<=kk)h+=1000;
                    else h++;
                }
                    int hh=h;
                    h=1;
                    while(m[h]<b&&h<=kk)
                {
                    if(m[h+1000]<b&&h+1000<=kk)h+=1000;
                    else h++;
                }
                if(m[h]!=b)h--;
                if(h<hh||h==hh)
            {
            if(h<hh)cout<<0<<endl;
            else cout<<1<<endl;
            continue;
        }
        cout<<h-hh+1<<endl;
    }
    return 0;
}