#include <bits/stdc++.h>
using namespace std;
long long primeFactor[5000005], preSum[5000005];
void seive() {
  primeFactor[0] = 1;
  primeFactor[1] = 1;
  for (long long i = 2; i < 5000005; i++) {
    if (primeFactor[i] == 0) {
      primeFactor[i] = i;
      for (long long j = i * i; j < 5000005; j += i)
        if (primeFactor[j] == 0) primeFactor[j] = i;
    }
  }
}
void factorize() {
  seive();
  for (long long i = 2; i < 5000005; i++) {
    long long cnt = 1;
    long long temp = i / primeFactor[i];
    while (temp != 1) {
      temp /= primeFactor[temp];
      cnt++;
    }
    preSum[i] = cnt + preSum[i - 1];
  }
}
int main() {
  factorize();
  long long t;
  scanf("%I64d", &t);
  while (t--) {
    long long a, b;
    scanf("%I64d%I64d", &a, &b);
    printf("%I64d\n", preSum[a] - preSum[b]);
  }
  return 0;
}
