#include <iostream>
using namespace std;

int main(){
   /*
   int ans = 0;
   int days[12] = {31,28,31,30,31,30,31,31,30,31,30,31};
   for(int i = 1;i <= 12;i++) for(int j = 1;j <= days[i - 1];j++) if(i == j / 10 + j % 10) ans++;
   cout << ans << endl;
   */
   cout << 30 << endl;
}