#include<stdio.h>
int main(){
    int month;
    scanf("%d"&month);
    if(month<1 || month>12){
        printf("Invalid input");
    }
    else{
        switch(month){
            case 1: case 3: case 7: case 8: case 10: case 12:
            print("30"):
            case 4: case 6: case 9: case 11:
            printf("30");
            printf("28 or 29");
            return 0;
        
        }
    }
}