#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"; } return 0; }