#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main() { int n; cin>>n; if (n < 1 || n > 12) { cout << "Invalid." << endl; } else { if (n == 1 || n == 3 || n == 5 || n == 7 || n == 8 || n == 10 || n == 12) { cout << 31 << endl; } else if (n == 4 || n == 6 || n == 9 || n == 11) { cout << 30 << endl; } else if (n == 2) { cout << 29 << endl; } } return 0; }