ll@n,a[3][128]{};
rep(i,3n){
	char@c;
	++a[i%3][c];
}
ll z=min(a[0]['c'],a[1]['o'],a[2]['n']);
if(z<n){
	z+=min(a[1]['c'],a[2]['o'],a[0]['n']);
	z+=min(a[2]['c'],a[0]['o'],a[1]['n']);
	z<?=n-1;
}
wt(z);