Problem 2 「偶数のフィボナッチ数」

euler2.d

import std.stdio;

int main(string[] argv) {
  int ct, a = 1, b = 1, c = 1;
  while(b <= 400_0000)
  {
    a = b+c;
    b = c;
    c = a;
    if (b % 2 == 0) ct += b;
  }
  writeln(ct);
  readln();
  return 0;
}