#include #include #include using namespace std; constexpr int mod = static_cast(powl(10, 9)) + 7; vector> dp, ndp; inline int calc_state(int less, int has3, int rem3) { return (rem3 << 2) | (has3 << 1) | less; } int f(const string &s, const int P) { const int length = static_cast(log10(P)) + 1; const int n = static_cast(s.size()); // dp[未満フラグ, has3, mod 3][mod P] := パターン数 dp.assign(12, vector(P, 0)); dp[0][0] = 1; for(int i=0; i(P, 0)); for(int less=0; less<2; ++less) { const int D = less ? 9 : s[i] - '0'; for(int has3=0; has3<2; ++has3) { for(int rem3=0; rem3<3; ++rem3) { int state = calc_state(less, has3, rem3); for(int remP=0; remP(s->size()); for(int i=n-1; i>=0; --i) { if(s->at(i) == '0') { s->at(i) = '9'; } else { --s->at(i); break; } } } int main(void) { string a, b; cin >> a >> b; minus1(&a); int P; scanf("%d", &P); int res = f(b, P) - f(a, P); res += mod; res %= mod; printf("%d\n", res); return 0; }