import sys input = sys.stdin.readline N,M=map(int,input().split()) E=[[] for i in range(N)] Distance=[[float("inf") for i in range(N)] for j in range(N)] for i in range(N): Distance[i][i]=0 for i in range(M): s,t,d=map(int,input().split()) s-=1 t-=1 E[s].append((t,d)) Distance[s][t]=min(Distance[s][t],d) for k in range(N): # k個までの町を使ってのDisが知れているときに for i in range(N): # 町iと for j in range(N): # 町jとの最短距離は、 length=Distance[i][k]+Distance[k][j] if Distance[i][j]>length: Distance[i][j]=length for i in range(N): S=0 for j in range(N): if Distance[i][j]==float("inf"): True else: S+=Distance[i][j] print(S)