func_code_string: #include <bits/stdc++.h>   using namespace std;   template <class T>   inline T abs(T a) {     return a > 0 ? a : -a;   }   int n;   int m;   int main() {     int last;     cin >> n >> last;     if (n == 1) {       if (last == 1) {         cout << 0 << endl <<  T  << endl;       } else {         cout <<  IMPOSSIBLE  << endl;       }       return 0;     }     int ans = -1;     int errans = 1e9;     for (int i = 1; i <= last; i++) {       int a = last, b = i;       int err = 0, len = 0;       while (b) {         err += (a / b) - 1;         len += a / b;         a %= b;         swap(b, a);       }       if (a != 1) continue;       err--;       if (len == n) {         if (errans > err) {           errans = err;           ans = i;         }       }     }     if (ans < 0) {       cout <<  IMPOSSIBLE  << endl;       return 0;     }     vector<int> res;     int a = last, b = ans;     while (b) {       res.push_back(a / b);       a %= b;       swap(b, a);     }     reverse((res).begin(), (res).end());     res[0]--;     cout << errans << endl;     cout <<  T ;     for (int i = 0; i < (((int)(res).size())); i++)       for (int j = 0; j < (res[i]); j++) printf( %c , ((i + 1) % 2 ?  B  :  T ));     printf(  n );     return 0;   }   