/* -*- coding: utf-8 -*-
 *
 * 2407.cc:  No.2407 Bouns 2.0 - yukicoder
 */

#include<cstdio>
#include<algorithm>

using namespace std;

/* constant */

/* typedef */

/* global variables */

/* subroutines */

/* main */

int main() {
  int w, z;
  char s[8];
  scanf("%d%d%s", &w, &z, s);

  int b = (s[0] - '0') * 10 + (s[2] - '0');
  int p = (w + z) / 10 * (b + 10);

  printf("%d\n", p);

  return 0;
}