#include <iostream>
#include <math.h>
using namespace std;

int main() {
    int v,t,p;
    cin >> v >> t >> p;
    int s = 0;
    int w = 0;
    int snr = 0;
    while (w < v) {
        w++; s++;
        if (snr > 0){
            snr--;
        }
        if (w == v && p > 0) {
        p--; w = 0;
        } else if (snr == 0){
        snr = t; w--;
        }
        for (int i = 12; i > 1; i--) {
            int thr = pow(10,i);
            if(v - w > thr && snr > thr) {
                w += thr; 
                s += thr;
                snr -= thr;
            }
        }
    }
    cout << s;
    return 0;
}