const char *WSPACE_SOURCE=R"(   
   
   
	
		   
				  	   
   
		    	
   
		    	 
   
		    		
   
		    	  
   
		    	 	
   
		 
   
   		
	
		   		
			 
    
				  	   		
 
			    
 
			    	  
	
		   	  
			 
    	
				  	
 	 	 
   	  
 
			    	
 
			    	 	
	
		   	 	
			 
    	 
				  	
 	 	 
   	 	
 
			    	 
 
			    	  
			   	 	
				    
    		
			 
		  	
		 	
   		
				      	
	      	 
	 		
	  	
   	
	    
 
		 
   	 	 
   			  		
   		  	 	
   	 		  	
	
  	
  	
  	
  



   	
   	 	 
   		 				
   	  			 
	
  	
  	
  



   	 
 
 
		 		

	

   		
  		
	  

	
)";

#include <cstdio>
#include <cstdint>
#include <cinttypes>
#include <cassert>

#include <iostream>
#include <map>
#include <stack>
#include <string>
#include <exception>

constexpr char SPACE=' ', TAB='\t', LINEFEED='\n';

struct CompileError: public std::exception {
  const std::string why;
  const size_t where;
  CompileError(const std::string &why, size_t where): why(why), where(where) {}
};

std::string tr(const std::string &src, char space, char tab, char linefeed) {
  std::string res="";
  for (char ch: src) {
    if (ch == space) {
      res += SPACE;
    } else if (ch == tab) {
      res += TAB;
    } else if (ch == linefeed) {
      res += LINEFEED;
    }
  }
  return res;
}

uint64_t parse_int(const std::string &src, size_t &i) {
  // XXX assume 64-bit integer, but specification requires arbitrary-
  //     precision integer

  char ch=src.at(i++);
  uint64_t n=0;
  if (ch == SPACE || ch == TAB) {
    while (src.at(i) != LINEFEED) {
      n = (n << 1) | (src.at(i++) == TAB);
    }
    if (ch == TAB) {
      n = -n;
    }
    ++i;
    return n;
  }
  throw CompileError("Invalid integer", i);
}

std::string int_to_bytes(uint64_t n) {
  std::string res(8, 0);
  for (size_t i=0; i<8; ++i) {
    res[i] = (unsigned char)(n & 255);
    n >>= 8;
  }
  return "q"+res;
}

uint64_t bytes_to_int(const std::string &b, size_t &i) {
  uint64_t n=0;
  if (b[i] == 'q') {
    int sh=0;
    while (sh < 64) {
      n |= uint64_t(b[++i] & 255) << sh;
      sh += 8;
    }
    ++i;
  }
  return n;
}

void stack_manipulation(std::string &res, const std::string &src, size_t &i) {
  char ch=src.at(i++);
  if (ch == SPACE) {
    // Push the number onto the stack
    res += "^" + int_to_bytes(parse_int(src, i));
    return;
  } else if (ch == LINEFEED) {
    ch = src.at(i++);
    if (ch == SPACE) {
      // Duplicate the top item on the stack
      res += "=";
      return;
    } else if (ch == TAB) {
      // Swap the top two items on the stack
      res += "~";
      return;
    } else if (ch == LINEFEED) {
      // Discard the top item on the stack
      res += "_";
      return;
    }
  }
  throw CompileError("Invalid stack manipulation", i);
}

void arithmetic(std::string &res, const std::string &src, size_t &i) {
  char ch=src.at(i++);
  if (ch == SPACE) {
    ch = src.at(i++);
    if (ch == SPACE) {
      res += "+";
      return;
    } else if (ch == TAB) {
      res += "-";
      return;
    } else if (ch == LINEFEED) {
      res += "*";
      return;
    }
  } else if (ch == TAB) {
    ch = src.at(i++);
    if (ch == SPACE) {
      res += "/";
      return;
    } else if (ch == TAB) {
      res += "%";
      return;
    }
  }
  throw CompileError("Invalid arithmetic", i);
}

void heap_access(std::string &res, const std::string &src, size_t &i) {
  char ch=src.at(i++);
  if (ch == SPACE) {
    // Store
    res += "!";
  } else if (ch == TAB) {
    // Retrieve
    res += "?";
  } else {
    throw CompileError("Invalid heap access", i);
  }
}

void flow_control(std::string &res, const std::string &src, size_t &i,
                  std::map<uint64_t, size_t> &label) {

  char ch=src.at(i++);
  if (ch == SPACE) {
    ch = src.at(i++);
    if (ch == SPACE) {
      // Mark a location in the program
      label[parse_int(src, i)] = res.size();
      return;
    } else if (ch == TAB) {
      // Call a subroutine
      res += "(" + int_to_bytes(parse_int(src, i));
      return;
    } else if (ch == LINEFEED) {
      // Jump unconditionally to a label
      res += "U" + int_to_bytes(parse_int(src, i));
      return;
    }
  } else if (ch == TAB) {
    ch = src.at(i++);
    if (ch == SPACE) {
      // Jump to a label if the top of the stack is zero
      res += "0" + int_to_bytes(parse_int(src, i));
      return;
    } else if (ch == TAB) {
      // Jump to a label if the top of the stack is negative
      res += "N" + int_to_bytes(parse_int(src, i));
      return;
    } else if (ch == LINEFEED) {
      // End a subroutine and transfer control back to the caller
      res += ")";
      return;
    }
  } else if (ch == LINEFEED && src.at(i++) == LINEFEED) {
    // End the program
    res += "$";
    return;
  }
  throw CompileError("Invalid flow control", i);
}

void io_access(std::string &res, const std::string &src, size_t &i) {
  char ch=src.at(i++);
  if (ch == SPACE) {
    ch = src.at(i++);
    if (ch == SPACE) {
      // Output the character at the top of the stack
      res += ".";
      return;
    } else if (ch == TAB) {
      // Output the number at the top of the stack
      res += "<";
      return;
    }
  } else if (ch == TAB) {
    ch = src.at(i++);
    if (ch == SPACE) {
      // Read a character and place it in the location given by the top
      // of the stack
      res += ",";
      return;
    } else if (ch == TAB) {
      // Read a number and place it in the location given by the top of
      // the stack
      res += ">";
      return;
    }
  }
  throw CompileError("Invalid I/O access", i);
}

std::string compile(const std::string &src,
                    std::map<uint64_t, size_t> &label) {

  std::string res="";
  size_t i=0;
  while (i < src.length()) {
    switch(src.at(i)) {
    case SPACE:
      stack_manipulation(res, src, ++i);
      break;

    case TAB:
      ++i;
      switch (src.at(i)) {
      case SPACE:
        arithmetic(res, src, ++i);
        break;

      case TAB:
        heap_access(res, src, ++i);
        break;

      case LINEFEED:
        io_access(res, src, ++i);
      }
      break;

    case LINEFEED:
      flow_control(res, src, ++i, label);
      if (res.back() == '$') break;
      break;

    default:
      (void)(0);  // maybe unreached, but not for sure
    }
  }
  return res;
}

void run(const std::string &code, const std::map<uint64_t, size_t> &label) {
  std::stack<uint64_t> stack;
  std::stack<size_t> callstack;
  std::map<size_t, uint64_t> heap;

  size_t i=0;
  char op;
  while (i < code.length()) {
    op = code.at(i++);
    switch (op) {
    case '^':
      stack.push(bytes_to_int(code, i));
      break;

    case '=':
      assert(!stack.empty());
      stack.push(uint64_t(stack.top()));
      break;

    case '~':
      assert(stack.size() >= 2);
      {
        uint64_t first=stack.top();
        stack.pop();
        uint64_t second=stack.top();
        stack.pop();
        stack.push(first);
        stack.push(second);
      }
      break;

    case '_':
      assert(!stack.empty());
      stack.pop();
      break;

    case '+':
    case '-':
    case '*':
    case '/':
    case '%':
      assert(stack.size() >= 2);
      {
        uint64_t rhs=stack.top();
        stack.pop();
        uint64_t lhs=stack.top();
        stack.pop();
        switch (op) {
        case '+': stack.push(lhs + rhs); break;
        case '-': stack.push(lhs - rhs); break;
        case '*': stack.push(lhs * rhs); break;
        case '/': stack.push(lhs / rhs); break;
        case '%': stack.push(lhs % rhs); break;
        }
      }
      break;

    case '!':
      assert(stack.size() >= 2);
      {
        uint64_t value=stack.top();
        stack.pop();
        size_t addr=stack.top();
        stack.pop();
        heap[addr] = value;
      }
      break;

    case '?':
      assert(!stack.empty());
      {
        size_t addr=stack.top();
        stack.pop();
        stack.push(heap[addr]);
      }
      break;

    case '(':
    case 'U':
    case '0':
    case 'N':
      {
        size_t lid=bytes_to_int(code, i);
        auto addrp=label.find(lid);
        assert(addrp != label.end());
        size_t addr=addrp->second;
        if (op == '(') {
          callstack.push(std::exchange(i, addr));
        } else if (op == 'U') {
          i = addr;
        } else {
          assert(!stack.empty());
          uint64_t top=stack.top();
          stack.pop();
          if ((op == '0' && top == 0) || (op == 'N' && (top >> 63))) {
            i = addr;
          }
        }
      }
      break;

    case ')':
      i = callstack.top();
      callstack.pop();
      break;

    case '$':
      return;

    case '.':
      putchar(stack.top());
      stack.pop();
      break;

    case '<':
      printf("%" PRId64, stack.top());
      stack.pop();
      break;

    case ',':
      assert(!stack.empty());
      heap[stack.top()] = getchar();
      stack.pop();
      break;

    case '>':
      assert(!stack.empty());
      scanf("%" SCNu64, &heap[stack.top()]);
      stack.pop();
      break;
    }
  }
}

int main(int argc, char *argv[]) {
  using namespace std::string_literals;
  std::string src;
  if (argc > 1) {
    FILE *fin;
    if (argv[1] != "-"s) {
      fin = fopen(argv[1], "r");
      if (!fin) return 1;
    } else {
      fin = stdin;
    }
    int ch;
    while ((ch = getc(fin)) != EOF)
      src += ch;

    fclose(fin);
  } else {
    src = WSPACE_SOURCE;
  }

  for (size_t i=0; i<src.length(); ++i) {
    if (src[i] > SPACE) {
      src = tr(src, 'S', 'T', 'L');
      break;
    }
  }

  std::map<uint64_t, size_t> label;
  std::string code;
  try {
    code = compile(src, label);
  } catch (CompileError &e) {
    printf("%zu: %s\n", e.where, e.why.c_str());
  }

  run(code, label);
}


Measured memory_bytes: 256