#pragma GCC optimize("Ofast")
#pragma GCC target("avx2")

#define rd_init() char*rp=({char*mmap();mmap(0l,1l<<25,1,2,0,0ll);})
#define rd() ({int _v=0,_c;while(_c=*rp++-48,_c>=0)_v=_v*10+_c;_v;})
#define wt(v) ({unsigned _z=v;do*--wp=_z%10+48;while(_z/=10);})
#define rrep(v,e) for(typeof(e) v=e;v--;)

typedef unsigned long ulong;

char wbuf[1<<25];

int main(){
	rd_init();
	int n=rd();
	int z=0;
	char*wp=wbuf+sizeof wbuf;
	*--wp='\n';
	rrep(i,n){
		if(rp[i]=='x'&&rp[i+1]=='o'){
			wt(i+2);
			*--wp=' ';
			++z;
		}
	}
	*--wp='\n';
	wt(z);
	write(1,wp,wbuf+sizeof wbuf-wp);
	_exit(0);
}