#include <stdio.h>
#include <stdint.h>

#define N 20

int main( int argc, char* argv[] )
{
   uint64_t r = 1;
   uint64_t i, j;

   for( i = 2; i <= N; ++i )
      if( (j = r%i) )
         r *= ( (i%j) ? i : (i/j) );

   printf( "\n%llu\n", r );

   return 0;
}