from sys import stdindef main(): inf = float(1e3000) l = [] a = l.append for s in stdin: a(s) n = len(l) nm = [None] * n nd = 0 for lj in l: nm[nd] = [inf] * n s = lj.split for k in s(): d = k.split(':') nb = int(d[0]) vt = int(d[1]) nm[nd][nb] = vt nd += 1 c = 0 sn = [{0:None},[e for e in nm[0]]] r = n-1 while r > 0: f = [inf, None] for i in xrange(n): if sn[1][i] < f[0]: f = [sn[1][i], i] c += f[0] sn[0][f[1]] = None for i in xrange(n): if i in sn[0]: sn[1][i] = inf else: sn[1][i] = min(sn[1][i], nm[f[1]][i]) r -= 1 print cmain()