#!/bin/bash

read -a arr
while [ ${#arr[@]} -eq 2 ]
    do
        sum=$((${arr[0]} + ${arr[1]}))
        echo $sum
        read -a arr
    done

awk '
BEGIN{}
{
    if($2 in arr){
        arr[$2]+=1
    }else{
        arr[$2]=1
    } 
}
END{
    PROCINFO["sorted_in"]="@ind_str_asc"
    for(i in arr){
        if(arr[i] > 1){
            print(arr[i],i)
        }
    }
}


' nowcoder.txt | sort -k 1
exit 0