function [S] = Cipher2Plain(P)
% function [S] = Cipher2Plain(P)
% P is a 2-by-M matrix of integers between 0 and 25
% S is a string output, containing only capital letters 
% S is found after conversion of integers into characters 

[n,M] = size(P); % n = 2, M is found dynamically
for i = 1 : 2 
    for j = 1 : M
        switch P(i,j)
        case 1,
            V(i,j) = 'A';
        case 2,
            V(i,j) = 'B';
        case 3,
            V(i,j) = 'C';
        case 4,
            V(i,j) = 'D';
        case 5,
            V(i,j) = 'E';
        case 6,
            V(i,j) = 'F';
        case 7,
            V(i,j) = 'G';
        case 8,
            V(i,j) = 'H';
        case 9,
            V(i,j) = 'I';
        case 10,
            V(i,j) = 'J';
        case 11,
            V(i,j) = 'K';
        case 12,
            V(i,j) = 'L';
        case 13,
            V(i,j) = 'M';
        case 14,
            V(i,j) = 'N';
        case 15,
            V(i,j) = 'O';
        case 16,
            V(i,j) = 'P';
        case 17,
            V(i,j) = 'Q';
        case 18,
            V(i,j) = 'R';
        case 19,
            V(i,j) = 'S';
        case 20,
            V(i,j) = 'T';
        case 21,
            V(i,j) = 'U';
        case 22,
            V(i,j) = 'V';
        case 23,
            V(i,j) = 'W';
        case 24,
            V(i,j) = 'X';
        case 25,
            V(i,j) = 'Y';
        case 0,
            V(i,j) = 'Z';
        end
    end
end

k = 0;
for j = 1 : M
    for i = 1 : 2
        k = k+1;
        S(k) = V(i,j);
    end
end
