function f = letters(a)

[a1,a2]=size(a);


for j=1:a1
for i=1:a2
    if a(j,i)== 0
        x = 'A';
    elseif a(j,i) == 1;
        x = 'B';
    elseif a(j,i) == 2;
        x = 'C';
    elseif a(j,i) == 3;
        x = 'D';
    elseif a(j,i) == 4;
        x = 'E';
    elseif a(j,i) == 5;
        x = 'F';
    elseif a(j,i) == 6;
        x = 'G';
    elseif a(j,i) == 7;
        x = 'H';
    elseif a(j,i) == 8;
        x = 'I';
    elseif a(j,i) == 9;
        x = 'J';
    elseif a(j,i) == 10;
        x = 'K';
    elseif a(j,i) == 11;
        x = 'L';
    elseif a(j,i) == 12;
        x = 'M';
    elseif a(j,i) == 13;
        x = 'N';
    elseif a(j,i) == 14;
        x = 'O';
    elseif a(j,i) == 15;
        x = 'P';
    elseif a(j,i) == 16;
        x = 'Q';
    elseif a(j,i) == 17;
        x = 'R';
    elseif a(j,i) == 18;
        x = 'S';
    elseif a(j,i) == 19;
        x = 'T';
    elseif a(j,i) == 20;
        x = 'U';
    elseif a(j,i) == 21;
        x = 'V';
    elseif a(j,i) == 22;
        x = 'W';
    elseif a(j,i) == 23;
        x = 'X';
    elseif a(j,i) == 24;
        x = 'Y';
    elseif a(j,i) == 25;
        x = 'Z';
    end
    f(j,i)=x;
end
end
