Node To Far - Input

int main(void){
    while(scanf("%d",&N),N){
        F(N)scanf("%d%d",&a,&b);//a → b EDGE
        while(scanf("%d%d",&a,&b),a){
            //TODO
            printf("Case %d: %d nodes not reachable from node %d with TTL = %d.\n",++cc,C-S,h,b);
        }
    }
    return 0;
}