Try this code u will get the answer

int main() { /* Enter your code here. Read input from STDIN. Print output to STDOUT */
char a[100007]; int size; cin>>size;

while(size)
    {
    cin>>a;

    int l=strlen(a);
    int i=0,j=l-1;
    if(l%2==0)
        {

        for(i=0;i<j;i++)
            {
            if(a[i]==a[j])
                {
                j--;
                if(i==j)
                    {
                    cout<<"-1";
                    break;
                }

                }
            else if(a[i+1]==a[j])
                {
                   cout<<i;
                   break;
            }
            else
                {
                cout<<j;
                break;
            }
        }

    }
    else
        {
        for(i=0;i<=j;i++)
            {
            if(a[i]==a[j])
                {

                j--;
                 if(i==j)
                     {
                     cout<<"-1";
                    break;
                 }
                }
            else if(a[i+1]==a[j]&& a[j-1]==a[i])
                {
                   if(a[i+2]==a[j-1])
                   {   
                   cout<<i;
                   break;
                   }
                    else
                        {
                        cout<<j;
                        break;
                    }

            }

            else if(a[i+1]==a[j])
                {
                   cout<<i;
                   break;
            }
            else
                {
                cout<<j;
                break;
            }

            if(i+1==j)
            {
            cout<<"-1";
            break;

        }

        }
}
    cout<<"\n";

size--; } getch(); return 0; }