func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long maxn = 1e7 + 10, maxl = 20, mod = 1e9 + 7, base = 737,                   inf = 2e18 + 13;   int a, n, res[maxn], t[maxn];   int main() {     ios::sync_with_stdio(0);     cin.tie(0);     cin >> a >> n;     for (int i = 2; i < a + n; i++)       if (!t[i]) {         t[i] = i;         for (long long j = 1ll * i * i; j < a + n; j += i) t[j] = i;       }     res[1] = 1;     for (int i = 2; i < a + n; i++) {       res[i] = res[i / t[i]];       if (res[i] % t[i])         res[i] *= t[i];       else         res[i] /= t[i];     }     long long ans = 0;     for (int i = a; i < a + n; i++) ans += res[i];     cout << ans << endl;     return 0;   }   