#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 a; cin>>a; switch(a){ case 1: case 3: case 5: case 7: case 8: case 10: case 12: cout<<31; break; case 4: case 6: case 9: case 11: cout<<30; break; case 2: cout<<29; break; default: cout<<"lnvalid."; break; } return 0; }