#include #include using namespace std; #define MOD (int)1e9+7 #define rep(i,n) for(int i=0;i> a >> b; int fb, fa, ans; fb = ketaDP(1, b); for (int i = 1; i <= a.size(); i++) { if (a[a.size() - i] == '0') { a[a.size() - i] = '9'; } else { a[a.size() - i] -= 1; break; } } if (a[0] == '0') a.erase(a.begin()); fa = ketaDP(0, a); if (fa > fb) fb += MOD; cout << fb - fa << endl; return 0; }