func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = 1000000007;   const int MAX = 5000001;   unsigned int arr[MAX], P[MAX];   void sieve() {     unsigned int i, j, t, k;     arr[0] = arr[1] = 0;     for (i = 2; i < MAX; i++) arr[i] = i;     for (i = 4; i < MAX; i += 2) arr[i] = 2;     for (i = 3; i * i <= MAX; i += 2)       if (arr[i] == i)         for (j = i * i; j < MAX; j += 2 * i)           if (arr[j] == j) arr[j] = i;     for (i = 2; i < 5000001; i++) P[i] = P[i / arr[i]] + 1;     for (i = 2; i < 5000001; i++) P[i] += P[i - 1];   }   int main(void) {     sieve();     unsigned int tc, i, a, b;     scanf( %u , &tc);     for (i = 1; i <= tc; i++) {       scanf( %u %u , &a, &b);       printf( %u n , P[a] - P[b]);     }     return 0;   }   