func_code_string: #include <bits/stdc++.h>   using namespace std;   long long a, i, j, n, aux, cnt, ans, div1[10000010], v[10000010];   int main() {     cin >> a >> n;     v[1] = 1;     for (i = 3; i * i <= a + n - 1; i += 2)       if (!div1[i]) {         div1[i] = i;         for (j = i * i; j <= a + n - 1; j += 2 * i) div1[j] = i;       }     for (i = 2; i <= a + n - 1; i += 2) div1[i] = 2;     for (i = 2; i <= a + n - 1; i++) {       aux = i;       cnt = 0;       if (!div1[i]) div1[i] = i;       while (aux % div1[i] == 0) aux /= div1[i], cnt++;       v[i] = v[aux];       if (cnt & 1) v[i] *= div1[i];     }     for (i = a; i <= a + n - 1; i++) ans += v[i];     cout << ans;     return 0;   }   