#include <bits/stdc++.h>
using namespace std;
template <class T1>
void deb(T1 e1) {
  cout << e1 << endl;
}
template <class T1, class T2>
void deb(T1 e1, T2 e2) {
  cout << e1 << " " << e2 << endl;
}
template <class T1, class T2, class T3>
void deb(T1 e1, T2 e2, T3 e3) {
  cout << e1 << " " << e2 << " " << e3 << endl;
}
template <class T1, class T2, class T3, class T4>
void deb(T1 e1, T2 e2, T3 e3, T4 e4) {
  cout << e1 << " " << e2 << " " << e3 << " " << e4 << endl;
}
template <class T1, class T2, class T3, class T4, class T5>
void deb(T1 e1, T2 e2, T3 e3, T4 e4, T5 e5) {
  cout << e1 << " " << e2 << " " << e3 << " " << e4 << " " << e5 << endl;
}
template <class T1, class T2, class T3, class T4, class T5, class T6>
void deb(T1 e1, T2 e2, T3 e3, T4 e4, T5 e5, T6 e6) {
  cout << e1 << " " << e2 << " " << e3 << " " << e4 << " " << e5 << " " << e6
       << endl;
}
template <class T>
T gcd(const T a, const T b) {
  return (b ? gcd<T>(b, a % b) : a);
}
template <class T>
T lcm(const T a, const T b) {
  return (a / gcd<T>(a, b) * b);
}
struct node {
  long long x, y;
  node() {}
  node(long long x, long long y) : x(x), y(y) {}
  bool operator<(const node& p) const { return x < p.x; }
};
string s1, s2;
long long convert_10(long long n, string s) {
  long long l;
  l = s.size() - 1;
  long long x = 1, y = 0, p;
  for (long long i = l; i >= 0; i--) {
    if (s[i] >= '0' && s[i] <= '9')
      p = s[i] - '0';
    else
      p = 10 + s[i] - 'A';
    y += x * p;
    x *= n;
  }
  return y;
}
string convert_base(long long n, long long x) {
  string s = "";
  while (x > 0) {
    long long y = x % n;
    x /= n;
    char c;
    if (y > 9)
      c = 'A' + (y - 10);
    else
      c = '0' + y;
    s = c + s;
  }
  if (s == "") s = "0";
  return s;
}
string convert_roman(long long n) {
  string s = "";
  string one[10] = {"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"};
  string ten[10] = {"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"};
  string hundred[10] = {"",  "C",  "CC",  "CCC",  "CD",
                        "D", "DC", "DCC", "DCCC", "CM"};
  string thousand[4] = {"", "M", "MM", "MMM"};
  s += thousand[n / 1000];
  n %= 1000;
  s += hundred[n / 100];
  n %= 100;
  s += ten[n / 10];
  n %= 10;
  s += one[n];
  return s;
}
long long convert_num(string s) {
  long long x = 0;
  for (long long i = 0; i < s.size(); i++) x = x * 10 + s[i] - '0';
  return x;
}
int main() {
  long long i, j, k, l, x, y, z, t, m, n;
  cin >> n >> s1 >> s2;
  x = convert_10(n, s2);
  string s;
  if (s1 == "R") {
    s = convert_roman(x);
  } else {
    y = convert_num(s1);
    s = convert_base(y, x);
  }
  deb(s);
  return 0;
}
