Check if i and n - i doesn 't  contain k in them print i and n-i
if ( freqCount ( i . ToString ( ) , ( char ) ( k + 48 ) ) == 0 && freqCount ( ( n - i ) . ToString ( ) , ( char ) ( k + 48 ) ) == 0 ) { Console . Write ( " ( " + i + " , ▁ " + ( n - i ) + " ) " ) ; flag = 1 ; break ; } }