#include <bits/stdc++.h>   using namespace std;   bool iss(int d) {     for (int i = 2; i * i <= d; ++i)       if (d % i == 0) return false;     return true;   }   int main() {     int a, b, c;     scanf( %d%d%d , &a, &b, &c);     vector<int> simple;     for (int i = 2; i < 100; ++i)       if (iss(i)) simple.push_back(i);     vector<vector<int> > d(101);     for (int i = 1; i <= 100; ++i) {       d[i].resize(simple.size());       for (int j = 0, tmp = i; j < simple.size(); ++j)         while (tmp % simple[j] == 0) {           tmp /= simple[j];           d[i][j]++;         }     }     int ans = 0;     int mod = 1 << 30;     for (int i = 1; i <= a; ++i)       for (int j = 1; j <= b; ++j)         for (int k = 1; k <= c; ++k) {           int prod = 1;           for (int l = 0; l < simple.size(); ++l)             prod *= d[i][l] + d[j][l] + d[k][l] + 1;           ans = (ans + prod) % mod;         }     printf( %d n , ans);     return 0;   }   