#include <stdio.h>
long long int dp[36] = {0};
int main(){
int n;
scanf("%d", &n);
dp[0] = 1;
dp[1] = 1;
long long int k = 0;
long long sum = 0;
for(int i = 2; i < 35; i++){
for(int j = 0; j < i; j++ ){
dp[i] += dp[j] * dp[i-j-1];
}
}
printf("%lld", dp[n]);
return 0;
}
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