#include <bits/stdc++.h>
using namespace std;
long long n, dp[30][30];
string s;
long long ten[30];
string ans[30][30];
int main() {
  cin >> n >> s;
  reverse(s.begin(), s.end());
  ten[0] = 1;
  for (int i = 1; i <= 20; i++) ten[i] = ten[i - 1] * 10;
  dp[0][0] = 0;
  dp[1][0] = s[0] - '0';
  ans[1][0] = 'M';
  dp[0][1] = s[0] - '0';
  ans[0][1] = 'H';
  for (int i = 2; i <= n; i++) {
    long long q = (int)s[i - 1] - '0';
    dp[i][0] = dp[i - 1][0] + q * ten[i - 1];
    ans[i][0] = ans[i - 1][0];
    ans[i][0] += 'M';
    dp[0][i] = dp[0][i - 1] + q * ten[i - 1];
    ans[0][i] = ans[0][i - 1];
    ans[0][i] += 'H';
  }
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= n; j++) {
      long long q = (int)s[i + j - 1] - '0';
      long long m = dp[i - 1][j] + q * ten[i - 1];
      long long h = dp[i][j - 1] + q * ten[j - 1];
      if (m <= h) {
        dp[i][j] = h;
        ans[i][j] = ans[i][j - 1];
        ans[i][j] += 'H';
      } else {
        dp[i][j] = m;
        ans[i][j] = ans[i - 1][j];
        ans[i][j] += 'M';
      }
    }
  s = ans[n][n];
  reverse(s.begin(), s.end());
  cout << s << endl;
  return 0;
}
