func_code_string: #include <bits/stdc++.h>   using namespace std;   long long int mod = 1e18;   long long int mul(long long int a, long long int b) {     return ((a % mod) * (b % mod)) % mod;   }   long long int add(long long int a, long long int b) {     return ((a % mod) + (b % mod)) % mod;   }   long long int sub(long long int a, long long int b) {     return ((a % mod) - (b % mod) + mod) % mod;   }   long long int gcdExtended(long long int a, long long int b, long long int *x,                             long long int *y) {     if (a == 0) {       *x = 0, *y = 1;       return b;     }     long long int x1, y1;     long long int gcd = gcdExtended(b % a, a, &x1, &y1);     *x = y1 - (b / a) * x1;     *y = x1;     return gcd;   }   long long int modInverse(long long int b) {     long long int x, y;     long long int g = gcdExtended(b, mod, &x, &y);     if (g != 1) return -1;     return (x % mod + mod) % mod;   }   long long int modDivide(long long int a, long long int b) {     a = a % mod;     long long int inv = modInverse(b);     if (inv == -1)       return -1;     else       return (inv * a) % mod;   }   long long int expFactor2(long long int n, long long int p) {     long long int exponent = 0;     while (n % p == 0) {       exponent++;       n /= p;     }     return exponent;   }   void sieve(long long int n, vector<bool> &prime, vector<long long int> &p) {     prime[1] = 0;     for (long long int i = 2; i <= n; i++) {       if (prime[i]) {         for (long long int j = i; j <= n; j += i) {           if (j > i) prime[j] = 0;           p[j] += expFactor2(j, i);         }       }     }   }   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     long long int i, t, j, inp, n, a, b;     cin >> t;     vector<long long int> p(5000001, 0);     vector<bool> prime(5000001, 1);     sieve(5000001, prime, p);     for (i = 2; i <= 5000000; i++) {       p[i] += p[i - 1];     }     for (i = 0; i < t; i++) {       cin >> a >> b;       long long int ans = 0;       ans = p[a] - p[b];       cout << ans <<   n ;     }     return 0;   }   