#include using namespace std; using ull = unsigned long long; using ll = long long; using lli = long long int; using ld = long double; using pa = pair; using ppa = pair; #define SORT(v, n) sort(v, v + n); #define ALL(v) v.begin(), v.end() #define VSORT(v) sort(ALL(v)) #define GRESORT(v) sort(ALL(v), greater()) #define REVERSE(v) reverse(ALL(v)) #define overlap(v) v.erase(unique(ALL(v)), v.end()) #define debug(x) cout << #x << ": " << x << endl #define FOR(i, a, b) for (int i = (a); i < (b); i++) #define rep(i, n) FOR(i, 0, n) #define RFOR(i, a, b) for (int i = (b - 1); i >= a; i--) #define rrep(i, n) RFOR(i, 0, n) #define INF INT_MAX #define SUP INT_MIN #define mins(a, b) a = min(a, b) #define maxs(a, b) a = max(a, b) // 4近傍 // int dy[]={0, 1, 0, -1}; // int dx[]={1, 0, -1, 0}; // 8近傍 // int dy[]={0,0,1,-1,1,1,-1,-1}; // int dx[]={1,-1,0,0,1,-1,1,-1}; // const ll MOD = 1000000007; ll pow_mod(ll a, ll b, ll mod) { ll tmp = 1; a %= mod; if (b > 0) { tmp = pow_mod(a, b / 2, mod); if (b % 2) tmp = (((tmp * tmp) % mod) * a) % mod; else tmp = (tmp * tmp) % mod; } return tmp; } bool f(string x){ int n = 12346; rep(i,n) if(to_string(i) == x) return true; return false; } void solve() { string a,b; cin >> a >> b; // cout << a << " " << b << endl; cout << (f(a) && f(b) ? "OK" : "NG") << endl; } int main() { std::ios::sync_with_stdio(false); std::cin.tie(0); solve(); return 0; }