// editor2
#include <stdio.h>
 long long  factriol (int num )
 if ( n ==1 && n==0)
  scanf ( "lld",n)
    printf("invaild input ")
    
   else if 1 = 1
    printf( "invaild input ")
    
    int mail {
        for (i=i;i>n;++i) 
     scanf("lld",fact )
     fact * = n
     return 0;
    }