{"raw_statement":[{"iden":"problem statement","content":"There are $N$ people numbered $1,2,\\ldots,N$.\n$M$ parties were held. $k_i$ people attended the $i$\\-th $(1\\leq i \\leq M)$ party, and they were People $x_{i,1},x_{i,2},\\ldots,x_{i,k_i}$.\nDetermine if every two people attended the same party at least once."},{"iden":"constraints","content":"*   $2\\leq N \\leq 100$\n*   $1\\leq M \\leq 100$\n*   $2\\leq k_i \\leq N$\n*   $1\\leq x_{i,1}<x_{i,2}<\\ldots < x_{i,k_i}\\leq N$\n*   All values in the input are integers."},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$N$ $M$\n$k_1$ $x_{1,1}$ $x_{1,2}$ $\\ldots$ $x_{1,k_1}$\n$\\vdots$\n$k_M$ $x_{M,1}$ $x_{M,2}$ $\\ldots$ $x_{M,k_M}$"},{"iden":"sample input 1","content":"3 3\n2 1 2\n2 2 3\n2 1 3"},{"iden":"sample output 1","content":"Yes\n\nBoth Person $1$ and Person $2$ attended the $1$\\-st party.\nBoth Person $2$ and Person $3$ attended the $2$\\-nd party.\nBoth Person $1$ and Person $3$ attended the $3$\\-rd party.\nTherefore, every two people attended the same party at least once, so the answer is `Yes`."},{"iden":"sample input 2","content":"4 2\n3 1 2 4\n3 2 3 4"},{"iden":"sample output 2","content":"No\n\nPerson $1$ and Person $3$ did not attend the same party, so the answer is `No`."}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}