var f:array[0..101,0..101] of longint;

g:array[0..101,0..101] of boolean;

x,y:array[0..1001] of longint;

n,m,p,i,j,k,ans:longint;

function min(a,b:longint):longint;

begin

if a>b then exit(b); exit(a)

end;

begin

readln(n,m,p);

for i:=1 to p do readln(x[i],y[i]);

fillchar(f,sizeof(f),127);

g[n,m]:=true;

f[n,m]:=0;

for i:=1 to p do

for j:=x[i] to n do

for k:=y[i] to m do

if g[j,k] then

begin

f[j-x[i],k-y[i]]:=min(f[j-x[i],k-y[i]],f[j,k]+1);

g[j-x[i],k-y[i]]:=true;

end;

ans:=oo;

for i:=1 to m do ans:=min(ans,f[0,i]);

if ans=oo then writeln('mty zhen mei yong!')

else writeln(ans);

end.