
char dui_lie[100],zuo,you;
int zuobian,youbian,changdu;//?????? 

void qian_shou(int zuobian)//???? 
{
    for(youbian=zuobian+1;youbian<changdu;youbian++)
    {
                              if(dui_lie[youbian]==zuo || dui_lie[youbian]==you)
                              break;
    }//??????????????????????? 
    if(dui_lie[youbian]==you)
    {
                             dui_lie[zuobian]='*';
                             dui_lie[youbian]='*';
                             cout<<zuobian<<" "<<youbian<<endl;
    }//???????????????????????? 
    else
    {
        zuobian=youbian;
        qian_shou(zuobian);
    }//????????????????????????????? 
}



int main()
{
    
    int i;
    cin>>dui_lie;
    changdu=strlen(dui_lie);
    zuo=dui_lie[0];
    you=dui_lie[changdu-1];//???????????? 
    for(i=1;i<=changdu/2;i++) 
    {
                        zuobian=0;//??????????????? 
                        qian_shou(zuobian);
    } //??????????? 
return 0;
}


