#include<iostream>#include<cmath>#include<cstring>using namespace std;struct node{short s[120];};node f[61][61][61];int n;node add( node x , node y ){int len;len = max(x.s[0],y.s[0]);for ( int i = 1 ; i <= len ; ++i ){x.s[i] += y.s[i] ;x.s[i+1] += x.s[i] / 10 ;x.s[i] %= 10; }if ( x.s[len+1] > 0 ) x.s[0] = len+1 ;else x.s[0] = len ;return x;}int main(){ios::sync_with_stdio(false);memset(f,0,sizeof(f));for ( int i = 0 ; i <= 60 ; ++i )for ( int j = 0 ; j <= 60 ; ++j )for ( int k = 0 ; k <= 60 ; ++k )f[i][j][k].s[0] = 1 ;f[0][0][0].s[1] = 1 ;for ( int i = 1 ; i <= 60 ; ++i ){for ( int j = 0 ; j <= i ; ++j )for ( int k = 0 ; k <= j ; ++k){if ( i-1 >= j ) f[i][j][k] = add( f[i][j][k],f[i-1][j][k] );if ( j-1 >= k ) f[i][j][k] = add( f[i][j][k],f[i][j-1][k] );if ( k-1 >= 0 ) f[i][j][k] = add( f[i][j][k],f[i][j][k-1] ); }}while ( cin >> n ){for ( int i = f[n][n][n].s[0] ; i >= 1 ; --i )cout << f[n][n][n].s[i] ;cout << endl << endl;}}
