funcao distancia (real x, real y, real x2, real y2): real
    retorne ( (x2-x1)^2 + (y2-y1)^2 ) ^ 1/2

arquivo ent
aeroporto a
real lat, lon
leia lat
leia lon
ent <- abre ("aeroportos.txt")
enquanto nao fim (ent):
    a <- le_aero(ent)
    mostre sigla, distancia (ent.latitude, ent.longitude,
                             lat, lon)