C++ :

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cctype> 
using namespace std;
int a[30];
int main()
{
	char ch;
	cin>>ch;
	while(ch!='@')
	{
		if (isalpha(ch)) a[tolower(ch)-'a']++;
		cin>>ch;
	}
	for (ch='a';ch<='z';ch=ch+1)
		if (a[ch-'a'])
			cout<<ch<<' '<<a[ch-'a']<<endl;
	return 0;
}