Hello... i have a table, i want to remove rows which appear more then one time based on column one .

I need unique rows based on column one. can some help me to figure it out. thank you example: this is the data mention below

if true
  % code
13416777741  270876
13416777741  320544
13467512554  74089
13467516316  261958
13467517300  65354
13467517674  26081
13467517674  55068
end

i want it in this shape

if true
  % code
13416777741  320544
13467512554  74089
13467516316  261958
13467517300  65354
13467517674  26081
end