#include #include #include #include #include #include #include #include #include #include #include #include #include #define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl; #define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; typedef long long ll; template vector> vec2d(int n, int m, T v){ return vector>(n, vector(m, v)); } template vector>> vec3d(int n, int m, int k, T v){ return vector>>(n, vector>(m, vector(k, v))); } template void print_vector(vector v, char delimiter=' '){ if(v.empty()) { cout << endl; return; } for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter; cout << v.back() << endl; } ll cb[105][105]; void init(){ cb[0][0] = 1; for(int x = 1; x <= 100; x++){ cb[x][0] = 1; for(int y = 1; y <= x; y++){ cb[x][y] = cb[x-1][y]+cb[x-1][y-1]; } } } ll naive(int n, int m){ ll ans = 0; for(int x = m; x >= 0; x--){ int sgn = (m-x)%2 == 0 ? 1 : -1; ll pw = 1; for(int i = 0; i < n; i++) pw *= x; ans += sgn*pw*cb[m][x]; // debug_value(ans) } return ans; } int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << setprecision(10) << fixed; init(); int n, m; cin >> n >> m; // cout << naive(n, m) << endl; // cout << (ll)1e18 << endl; if(m > n) cout << 0 << endl; else cout << naive(n, m) << endl; }