#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using ull = unsigned long long;
ll MAX(ll a, ll b, ll c) { return max(a, max(b, c)); }
ll MIN(ll a, ll b, ll c) { return min(a, min(b, c)); }
const int dx[4] = {0, 1, 0, -1};
const int dy[4] = {1, 0, -1, 0};
template <class T>
inline bool chmax(T& a, T& b) {
  if (a < b) {
    a = b;
    return true;
  } else
    return false;
}
template <class T>
inline bool chmin(T& a, T& b) {
  if (a > b) {
    a = b;
    return true;
  } else
    return false;
}
int main() {
  int a, b;
  cin >> a >> b;
  0 < a&& a < 10 && 0 < b&& b < 10 ? cout << a * b << endl
                                   : cout << "No" << endl;
}
