diff --git a/solexafiller.go b/solexafiller.go
new file mode 100644
index 0000000..39c0823
--- /dev/null
+++ b/solexafiller.go
@@ -0,0 +1,129 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"sort"
+	"strconv"
+	"strings"
+)
+
+type (
+	name_size_pair struct {
+		name string
+		size uint64
+	}
+	jbod    = name_size_pair
+	proj    = name_size_pair
+	mapping []uint64
+)
+
+func new_name_size_pair(data string) name_size_pair {
+	var s uint64
+
+	d := strings.Split(data, ",")
+
+	if len(d) != 2 {
+		panic("wrong file format!")
+	}
+
+	s, e := strconv.ParseUint(d[1], 10, 64)
+	if e != nil {
+		panic("wrong format for size!\n" + e.Error())
+	}
+
+	return name_size_pair{d[0], s}
+}
+
+func read_data(sc *bufio.Scanner) ([]jbod, []proj) {
+	var (
+		js []jbod
+		ps []proj
+	)
+
+	for sc.Scan() {
+		da := strings.Split(sc.Text(), ":")
+		if len(da) != 2 {
+			panic("wrong file format!")
+		}
+
+		js = append(js, new_name_size_pair(da[0]))
+
+		for _, p := range strings.Split(da[1], ";") {
+			if p == "" {
+				continue
+			}
+			ps = append(ps, new_name_size_pair(p))
+		}
+	}
+
+	if er := sc.Err(); er != nil {
+		panic(er)
+	}
+
+	return js, ps
+}
+
+func write_data(m mapping, js []jbod, ps []proj) {
+	var p []string
+
+	for i := 0; i < len(js); i++ {
+		fmt.Printf("%s,%d:", js[i].name, js[i].size)
+		p = p[:0]
+		for k, j := range m {
+			if j == uint64(i) {
+				p = append(p, fmt.Sprintf("%s,%d", ps[k].name, ps[k].size))
+			}
+		}
+		fmt.Println(strings.Join(p, ";"))
+	}
+}
+
+func first_fit_decreasing(js []jbod, ps []proj) mapping {
+	var (
+		m mapping  = make([]uint64, len(ps))
+		c []uint64 = make([]uint64, len(js))
+	)
+
+	sort.Slice(ps, func(i, j int) bool {
+		return ps[i].size > ps[j].size
+	})
+
+	sort.Slice(js, func(i, j int) bool {
+		return js[i].size < js[j].size
+	})
+
+	for i := 0; i < len(ps); i++ {
+		for j := 0; j < len(js); j++ {
+			c[j] += ps[i].size
+			if c[j] <= js[j].size {
+				m[i] = uint64(j)
+				break
+			}
+			c[j] -= ps[i].size
+			if j + 1 == len(js) && i + 1 == len(ps) {
+				m = make([]uint64, len(js))
+			}
+		}
+	}
+
+	return m
+}
+
+func main() {
+	var (
+		js []jbod
+		ps []proj
+	)
+
+	stat, _ := os.Stdin.Stat()
+	if stat.Mode()&os.ModeCharDevice == 0 {
+		js, ps = read_data(bufio.NewScanner(os.Stdin))
+	} else {
+		panic("no input")
+	}
+
+	m := first_fit_decreasing(js, ps)
+	write_data(m, js, ps)
+}