C++ :

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;

struct node
{
    char s[30];
    int dep;
} list1[5010],list2[5010];

char a[7][30],b[7][30];
int n;
bool check(char *s1,char *s2)
{
    if (strlen(s1)!=strlen(s2)) return false;
    for (int i=0;i<strlen(s1);i++)
        if (s1[i]!=s2[i]) return false;
    return true;
}
bool pan1(char *s,int i,int x)
{
    for (int j=i;j<i+strlen(a[x]);j++)
        if (s[j]!=a[x][j-i]) return false;
    return true;
}
bool pan2(char *s,int i,int x)
{
    for (int j=i;j<i+strlen(b[x]);j++)
        if (s[j]!=b[x][j-i]) return false;
    return true;
}
void bfs()
{
    int head1,tail1,head2,tail2,i,j,k,l;
    head1=tail1=head2=tail2=1;

    while (head1<=tail1 && head2<=tail2)
    {
        if (list1[head1].dep+list2[head2].dep>10)
        {
            printf("NO ANSWER!\n");
            return ;
        }
        for ( i=0;i<strlen(list1[head1].s);i++)
            for ( j=1;j<=n;j++)
                if (pan1(list1[head1].s,i,j))
                {
                  tail1++;
                  for (k=0;k<i;k++) list1[tail1].s[k]=list1[head1].s[k];

                  for (l=0;l<strlen(b[j]);l++,k++) list1[tail1].s[k]=b[j][l];

                  for (l=i+strlen(a[j]);l<=strlen(list1[head1].s);l++,k++)
                     list1[tail1].s[k]=list1[head1].s[l];

                  list1[tail1].s[k]='\0';
                  list1[tail1].dep=list1[head1].dep+1;

                  for (k=1;k<=tail2;k++)
                    if (check(list1[tail1].s,list2[k].s))
                    {
                       printf("%d\n",list1[tail1].dep+list2[k].dep);
                       return ;
                     }
                }

        for ( i=0;i<strlen(list2[head2].s);i++)
            for ( j=1;j<=n;j++)
                if (pan2(list2[head2].s,i,j))
                {
                  tail2++;
                  for (k=0;k<i;k++) list2[tail2].s[k]=list2[head2].s[k];
                  for ( l=0;l<strlen(a[j]);l++,k++) list2[tail2].s[k]=a[j][l];
                  for (l=i+strlen(b[j]);l<=strlen(list2[head2].s);l++,k++)
                    list2[tail2].s[k]=list2[head2].s[l];
                  list2[tail2].s[k]='\0';
                  list2[tail2].dep=list2[head2].dep+1;
                  for (k=1;k<=tail1;k++)
                    if (check(list1[k].s,list2[tail2].s))
                    {
                       printf("%d\n",list1[k].dep+list2[tail2].dep);
                       return ;
                    }
                }
        head1++; head2++;
    }
    printf("NO ANSWER!\n");
}

int main()
{

    scanf("%s%s",list1[1].s,list2[1].s);
    n=1;
    while (scanf("%s%s",a[n],b[n])!=EOF) n++;
    n--;
    list1[1].dep=list2[1].dep=0;
    bfs();
    return 0;
}

Pascal :

const
 maxn=2300;
type
 node=record  
  str:string;
  dep:longint;
 end;
 ctype=array[1..maxn]of ^node;
 bin=0..1;
var
 maxk:byte;c:array [0..1]of ctype;
 x0:array[0..6,0..1]of string;
 open,guan:array [0..1] of longint;
procedure init;
var
 temp:string;
 i,j:longint;
begin
 for i:=0 to 1 do
  for j:=1 to maxn do
   new(c[i,j]);
 i:=0;
 while not eof and (i<=6) do
 begin
  readln(temp);
  x0[i,0]:=copy(temp,1,pos(' ',temp)-1);
  x0[i,1]:=copy(temp,pos(' ',temp)+1,length(temp));
  inc(i);
 end;
 maxk:=i-1;
end;
procedure calc;
var
 st:bin;
 d:string;
procedure bool(st:bin);
var
 i:longint;
begin
 if x0[0,1-st]=c[st,guan[st]]^.str then
 begin
  writeln(c[st,guan[st]]^.dep);
  halt;
 end;
 for i:=1 to guan[1-st] do
  if c[st,guan[st]]^.str=c[1-st,i]^.str then
  begin
   writeln(c[st,guan[st]]^.dep+c[1-st,i]^.dep);
   halt;
  end;
end;
procedure checkup(st:bin);
var
 i:longint;
begin
 for i:=1 to guan[st]-1 do
  if c[st,i]^.str=c[st,guan[st]]^.str then
  begin
   dec(guan[st]);
   exit;
  end;
 bool(st);
end;
procedure expand(st:bin);
var
 i,j,k,lx,ld:longint;
begin
 inc(open[st]);
 d:=c[st,open[st]]^.str;
 k:=c[st,open[st]]^.dep;
 ld:=length(d);
 for i:=1 to maxk do
 begin
  lx:=length(x0[i,st]);
  for j:=1 to ld do
  begin
   if (copy(d,j,lx)=x0[i,st]) and (length(copy(d,1,j-1)+x0[i,1-st]+copy(d,j+lx,ld))<=115) then
   begin
    if guan[st]>=maxn then exit;
    inc(guan[st]);
    c[st,guan[st]]^.str:=copy(d,1,j-1)+x0[i,1-st]+copy(d,j+lx,ld);
    c[st,guan[st]]^.dep:=k+1;
    checkup(st);
   end;
  end;
 end;
end;
begin
 for st:=0 to 1 do
 begin
  open[st]:=0;
  guan[st]:=1;
  c[st,guan[st]]^.str:=x0[0,st];
  c[st,guan[st]]^.dep:=0;
  bool(st);
 end;
 repeat
  if (open[0]<=open[1]) and not ((open[0]>=guan[0]) or (guan[0]>=maxn) or (c[0,guan[0]]^.dep>10)) then expand(0);
  if (open[1]<=open[0]) and not ((open[1]>=guan[1]) or (guan[1]>=maxn) or (c[1,guan[1]]^.dep>10)) then expand(1);
  if not ((open[0]>=guan[0]) or (guan[0]>=maxn) or (c[0,guan[0]]^.dep>10)) then expand(0);
  if not ((open[1]>=guan[1]) or (guan[1]>=maxn) or (c[1,guan[1]]^.dep>10)) then expand(1);
 until (open[0]>=guan[0]) or (c[0,guan[0]]^.dep>10) or (guan[0]>=maxn) and (guan[1]>=maxn) or (open[1]>=guan[1]) or (c[1,guan[1]]^.dep>10);
end;
begin
 init;
 calc;
 writeln('NO ANSWER!');
end.