void eclass(int nf[], int n, int lista[], int listb[], int m){	int l,k,j;	for (k=1;k<=n;k++) nf[k]=k;	for (l=1;l<=m;l++) {		j=lista[l];		while (nf[j] != j) j=nf[j];		k=listb[l];		while (nf[k] != k) k=nf[k];		if (j != k) nf[j]=k;	}	for (j=1;j<=n;j++)		while (nf[j] != nf[nf[j]]) nf[j]=nf[nf[j]];}