var n,m,i,j,k,x,y,cuv:longint;
    re:array[1..26,1..26]of byte;
    l1,l2,c:char;
    a:array[1..1000,1..26]of longint;
begin
assign(input,'nrcuv.in');
reset(input);
readln(n,m);
for i:=1 to m do
begin
     readln(l1,c,l2);
     x:=ord(l1-'a')+1;
     y:=ord(l2-'a')+1;
     re[x,y]:=1;
     re[y,x]:=1;
end;
close(input);
for k:=1 to 26 do
a[1,k]:=1;
for i:=2 to n do
begin
     for j:=1 to 26 do
     begin
          for k:=1 to 26 do
              if(re[j,k]=0)then
              a[i,j]:=a[i,j]+1;
     end;
end;
for k:=1 to 26 do
cuv:=cuv+a[n,k];
assign(output,'nrcuv.out');
rewrite(output);
writeln(cuv);
close(output);
end.