~cpp #include<iostream> using namespace std; int pa(int x, int y); // 각 int main() { int a,b; while(cin>> a >> b) { cout<<pa(a, b)<<endl ; } return 0; } int pa(int x, int y) { return (x<=2 || x==y || y==1 ) ? 1 : pa(x-1,y-1) + pa(x-1,y); }