#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; if (a>=1&&a<=12){ 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;} } else{ cout<<"Invalid."; } return 0; }