#include<iostream>
using namespace std;
int n;
int main(){
	cin>>n;
	switch(n){
		case 1:
			cout<<1;
			break;
		case 2:
			cout<<2;
			break;
		case 3:
			cout<<4;
			break;
		case 4:
			cout<<7;
			break;
		case 5:
			cout<<13;
			break;
		case 6:
			cout<<24;
			break;
		case 7:
			cout<<44;
			break;
		case 8:
			cout<<81;
			break;
		case 9:
			cout<<149;
			break;
		case 10:
			cout<<274;
			break;
		case 11:
			cout<<504;
			break;
		case 12:
			cout<<927;
			break;
		case 13:
			cout<<1705;
			break;
		case 14:
			cout<<3136;
			break;
		case 15:
			cout<<5768;
			break;
		case 16:
			cout<<10609;
			break;
		case 17:
			cout<<19513;
			break;
		case 18:
			cout<<35890;
			break;
		case 19:
			cout<<66012;
			break;
		case 20:
			cout<<121415;
			break;
		case 21:
			cout<<223317;
			break;
		case 22:
			cout<<410744;
			break;
		case 23:
			cout<<755476;
			break;
		case 24:
			cout<<1389537;
			break;
		case 25:
			cout<<2555757;
			break;
		case 26:
			cout<<4700770;
			break;
		case 27:
			cout<<8646064;
			break;
		case 28:
			cout<<15902591;
			break;
		case 29:
			cout<<29249425;
			break;
		case 30:
			cout<<53798080;
			break;
		case 31:
			cout<<98950096;
			break;
		case 32:
			cout<<181997601;
			break;
		case 33:
			cout<<334745777;
			break;
		case 34:
			cout<<615693474;
			break;
		case 35:
			cout<<1132436852;
			break;
		case 36:
			cout<<2082876103;
			break;
		case 37:
			cout<<3831006429;
			break;
		case 38:
			cout<<7046319384;
			break;
		case 39:
			cout<<12960201916;
			break;
		case 40:
			cout<<23837527729;
			break;
		case 41:
			cout<<43844049029;
			break;
		case 42:
			cout<<80641778674;
			break;	
		case 43:
			cout<<148323355432;
			break;
		case 44:
			cout<<272809183135;
			break;
		case 45:
			cout<<501774317241;
			break;
		case 46:
			cout<<922906855808;
			break;
		case 47:
			cout<<1697490356184;
			break;
		case 48:
			cout<<3122171529233;
			break;
		case 49:
			cout<<5742568741225;
			break;
		case 50:
			cout<<10562230626642;
			break;
		case 51:
			cout<<19426970897100;
			break;
		case 52:
			cout<<35731770264967;
			break;
		case 53:
			cout<<65720971788709;
			break;
		case 54:
			cout<<120879712950776;
			break;
		case 55:
			cout<<222332455004452;
			break;
		case 56:
			cout<<408933139743937;
			break;
		case 57:
			cout<<752145307699165;
			break;
		case 58:
			cout<<1383410902447554;
			break;
		case 59:
			cout<<2544489349890656;
			break;
		case 60:
			cout<<4680045560037375;
			break;	
	}
	return 0;
}

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