#include <stdio.h>


int main(void) {
    int month, happyday, i;
    i = 1;
    happyday = 0;
    for (month = 12; month > 0; month--) {;
      while (month >  0) {
        month = month - i;
        i++;
        happyday++;
        }
    }
    printf("%d\n", happyday);


    return 0;
}