發送短信 : Two-echelon vehicle routing problem for post-disaster aid

  _  _    _    _    _    _    __   __    _____   
 | \| || | || | || | || | ||  \ \\/ //  /  ___|| 
 |  ' || | || | || | || | ||   \ ` //  | // __   
 | .  || | \\_/ || | \\_/ ||    | ||   | \\_\ || 
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 `-` -`    `---`     `---`      `-`'     `---`