#include <stdio.h>

int main () {
  int w = 0;
  int z = 0;
  char b[4] = "";
  
  int res = 0;
  
  int ans = 0;
  
  res = scanf("%d", &w);
  res = scanf("%d", &z);
  res = scanf("%s", b);
  
  ans = 10+((int)(b[0]-'0'))*10+((int)(b[2]-'0'));
  ans *= (w+z)/10;
  
  printf("%d\n", ans);
  return 0;
}