func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MOD = 1073741824;   const int N = 100005;   const double PI = 4 * atan(1);   int dx[] = {1, -1, 0, 0, 1, -1, 1, -1};   int dy[] = {0, 0, 1, -1, 1, 1, -1, -1};   long long gcd(long long a, long long b) { return (b == 0 ? a : gcd(b, a % b)); }   long long lcm(long long a, long long b) { return a * (b / gcd(a, b)); }   bool issquare(long long w) { return trunc(sqrt(w)) * trunc(sqrt(w)) == w; }   bool isprime(long long u) {     for (long long i = 2; i <= (int)sqrt(u); i++) {       if (u % i == 0) return 0;     }     return 1;   }   long long mod(long long to_mod) {     to_mod %= MOD;     while (to_mod < 0) to_mod += MOD;     return to_mod % MOD;   }   long long moduloMultiplication(long long a, long long b, long long mod) {     long long res = 0;     a %= mod;     while (b) {       if (b & 1) res = (res + a) % mod;       a = (2 * a) % mod;       b >>= 1;     }     return res;   }   long long power(long long x, long long y) {     long long res = 1;     x = x;     while (y > 0) {       if (y & 1) res = (res * x);       y = y >> 1;       x = (x * x);     }     return res;   }   long long _sieve_size;   bitset<1000010> bs;   vector<long long> primes;   void sieve(long long upperbound) {     _sieve_size = upperbound + 1;     bs.set();     bs[0] = bs[1] = 0;     for (long long i = 2; i <= _sieve_size; i++)       if (bs[i]) {         for (long long j = i * i; j <= _sieve_size; j += i) bs[j] = 0;         primes.push_back(i);       }   }   long long numDiv(long long N) {     long long PF_idx = 0, PF = primes[PF_idx], ans = 1;     while (PF * PF <= N) {       long long power = 0;       while (N % PF == 0) {         N /= PF;         power++;       }       ans *= (power + 1);       PF = primes[++PF_idx];     }     if (N != 1) ans *= 2;     return ans;   }   int main() {     sieve(1000000);     long long t[1000005];     for (int i = 1; i <= 1000000; i++) {       t[i] = numDiv(i);     }     long long a, b, c, ans = 0;     cin >> a >> b >> c;     for (int i = 1; i <= a; i++) {       for (int j = 1; j <= b; j++) {         for (int k = 1; k <= c; k++) {           ans = mod(ans + t[i * j * k]);         }       }     }     cout << ans;     return 0;   }   