Osajono

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

// g++ ...
#define __STDC_FORMAT_MACROS
#include <inttypes.h>

uint64_t summa(int i)
{
    uint64_t x;
    uint64_t s = 0;
    for(x = (uint64_t)i; x > 0; --x)
        s += x;

    return s;
}

int main()
{
    int i, j, k;
    uint64_t tuloste = 0;
    char syote[128000];

    if(fgets(syote, sizeof(syote), stdin) != 0)
    {
        for(i = 'A'; i < 'Z' + 1; ++i)
        {
            k = 0;
            for(j = 0; syote[j] != 0; ++j)
                if(syote[j] == i || syote[j] == i + 32) // A-Z, a-z
                    ++k;

            tuloste += summa(k);
        }
    }

    printf("%" PRIu64 "\n", tuloste);
    return 0;
}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: ACCEPTED

Test 12

Group: 3

Verdict: ACCEPTED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED