import algorithm, complex, macros, math, sequtils, sets, strutils, tables

macro unpack*(rhs: seq, cnt: static[int]): auto =
  let v = genSym(); result = quote do:(let `v` = `rhs`;())
  if NimMajor == 0 and NimMinor <= 17:
    for i in 0..<cnt: result[0][1].add(quote do:`v`[`i`])
  else:
    for i in 0..<cnt: result[1].add(quote do:`v`[`i`])

template input*(T: typedesc, cnt: Natural = 1): untyped =
  let line = stdin.readLine.split(" ")
  when T is int:         line.map(parseInt).unpack(cnt)
  elif T is float:       line.map(parseFloat).unpack(cnt)
  elif T is string:      line.unpack(cnt)
  elif T is char:        line.mapIt(it[0]).unpack(cnt)
  elif T is seq[int]:    line.map(parseint)
  elif T is seq[float]:  line.map(parseFloat)
  elif T is seq[string]: line
  elif T is seq[char]:   line.mapIt(it[0])

# -------------------------------------------------- #

import std/editdistance
let (N, M) = input(int, 2)
let S, T = input(string)
echo editDistance(S, T)