contract charNumberPair
{
    string public char;
    uint256 public repeatCount;

    constructor(string memory ch) public {
        char = ch;
        repeatCount = 0;
    }

    function incrementRepeatCount() public
    {
        repeatCount++;
    }

    function getChar() public returns (string memory)
    {
        return char;
    }

    function getRepeatCount() public returns (uint256)
    {
        return repeatCount;
    }
}

contract main
{
    string public txt;
    string public txtlength;

    function getSlice(uint256 begin, uint256 end, string memory text) public pure returns (string memory) {
        bytes memory a = new bytes(end-begin+1);
        for(uint i=0;i<=end-begin;i++){
            a[i] = bytes(text)[i+begin-1];
        }
        return string(a);
    }

    function compareStrings(string memory a, string memory b) public view returns (bool) {
    return (keccak256(abi.encodePacked((a))) == keccak256(abi.encodePacked((b))));
}

    function setInput(string memory input, string memory lengthInput) public
    {
        txt = input;
        txtlength = lengthInput;
    }

    function mainFunc() public
    {
        uint len = 52;
        string memory alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
        charNumberPair[52] memory pairs;

        uint begin = 0;
        uint end = 2;

        for (uint i = 0; i < len; i++)
        {
            string memory temp = getSlice(begin, end, alphabet);
            pairs[i] = new charNumberPair(temp);
            begin++;
            end++;
        }

        for (uint i = 0; i < len; i++)
        {
            begin = 0;
            end = 2;
            for (uint i2 = 0; i2 < 0; i2++)
            {
                string memory temp = getSlice(begin, end, txt);
                string memory temp2 = pairs[i].getChar();
                if (compareStrings(temp2, temp))
                    {
                        pairs[i].incrementRepeatCount();
                    }
                begin++;
                end++;
            }
        }

        for (uint write = 0; write < len; write++)
            {
                for (uint sort = 0; sort < len - 1; sort++)
                {
                    uint256 t1 = pairs[sort].getRepeatCount();
                    uint256 t2 = pairs[sort + 1].getRepeatCount();
                    if (t1 > t2)
                    {
                        charNumberPair temp = pairs[sort + 1];
                        pairs[sort + 1] = pairs[sort];
                        pairs[sort] = temp;
                    }
                }
            }
    }
}