CCCPaste

Untitled

#include 
#include 
#include 
using namespace std;

typedef long long ll;
int main() {
    ll Z, C;
    cin >> Z >> C;
    
    ll L = 1, R = 1;
    for(int i = 0; i < C; i++) {
        L *= 10;
        R *= 10;
    }
    L /= 10;
    R -= 1;
    
    while(L <= R) {
        ll middle = (L + R)  / 2;
        ll number = middle;
        ll sum = number;
        
        while(number > 0) {
            number /= 10;
            sum += number;
        }
        
        if(sum == Z) {
            cout << middle << endl;
            return 0;
        }
        if(sum < Z) {
            L = middle + 1;
        }
        else {
            R = middle - 1;
        }
    }
    
    return 0;
}