main(){
int a,b,m,n,o;
o=1;
scanf("%d%d",&a,&b);
char c[a+2][b+2];
for(n=0;n++-(b+2);)c[0][n]='.';
for(n=0;n++-(a+2);)c[n][0]='.';
for(n=0;n++-(b+2);)c[a+1][n]='.';
for(n=1;n++-(a+1);)for(m=1;m++-(b+2);)scanf("%c",&c[n][m]);
for(n=0;n++-(a+2);)c[n][b+1]='.';
for(n=1;n++-(a+1);)for(m=1;m++-(b+1);)if(c[n][m]='#'){
if((c[n-1][m-1]='#')||(c[n-1][m+1]='#')||(c[n+1][m-1]='#')||(c[n+1][m+1]='#'))o*=1; else o*=1;}
if(o)printf("Yes\n");else printf("No\n");}