input: Write a python function to generate a string that concatenates two digits and a sequence of digits from 0 to 9.
  assert generate_string() == "0001234567890101234567890201234567890301234567890401234567890501234567890601234567890701234567890801234567890901234567891001234567891101234567891201234567891301234567891401234567891501234567891601234567891701234567891801234567891901234567892001234567892101234567892201234567892301234567892401234567892501234567892601234567892701234567892801234567892901234567893001234567893101234567893201234567893301234567893401234567893501234567893601234567893701234567893801234567893901234567894001234567894101234567894201234567894301234567894401234567894501234567894601234567894701234567894801234567894901234567895001234567895101234567895201234567895301234567895401234567895501234567895601234567895701234567895801234567895901234567896001234567896101234567896201234567896301234567896401234567896501234567896601234567896701234567896801234567896901234567897001234567897101234567897201234567897301234567897401234567897501234567897601234567897701234567897801234567897901234567898001234567898101234567898201234567898301234567898401234567898501234567898601234567898701234567898801234567898901234567899001234567899101234567899201234567899301234567899401234567899501234567899601234567899701234567899801234567899901234567899"
output: def generate_string():
      return ''.join(f'{i:02}0123456789' for i in range(100))