#include #include #include #define REP(i,s,n) for(int i=(int)(s);i<(int)(n);i++) using namespace std; typedef __int64_t ll; int m; /* Returns the next state from st. */ int next_state(int st, char ch) { if (st == 2) { // fail return 2; } if (st == 1) { // "0" return 2; // This automaton never accepts string of form /0..*/ } if (st == 0) { // init, "" if (ch == '0') { return 1; // "0" } return (ch - '0') % m + 3; } int q = st - 3; return (q * 10 + (ch - '0')) % m + 3; } const int M = 101000; ll dp[2][M] = {}; const ll mod = 1e9 + 7; int main(void){ string s; cin >> s >> m; int len = s.length(); vector > dp(len + 1, vector (m + 3)); dp[0][0] = 1; /* invariant condition : t == (i - 1) % 2*/ REP (i, 1, len + 1) { REP (j, 0, m + 3) { dp[i][j] = dp[i - 1][j]; } REP (j, 0, m + 3) { int &d2 = dp[i][next_state(j, s[i - 1])]; d2 += dp[i - 1][j]; d2 %= mod; } } // accepting states are {1, 3} cout << (dp[len][1] + dp[len][3]) % mod << endl; }