{"raw_statement":[{"iden":"problem statement","content":"Takahashi has $N$ teeth, one in each of the holes numbered $1, 2, \\dots, N$.  \nDentist Aoki will perform $Q$ treatments on these teeth and holes.  \nIn the $i$\\-th treatment, hole $T_i$ is treated as follows:\n\n*   If there is a tooth in hole $T_i$, remove the tooth from hole $T_i$.\n*   If there is no tooth in hole $T_i$ (i.e., the hole is empty), grow a tooth in hole $T_i$.\n\nAfter all treatments are completed, how many teeth does Takahashi have?"},{"iden":"constraints","content":"*   All input values are integers.\n*   $1 \\le N, Q \\le 1000$\n*   $1 \\le T_i \\le N$"},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$N$ $Q$\n$T_1$ $T_2$ $\\dots$ $T_Q$"},{"iden":"sample input 1","content":"30 6\n2 9 18 27 18 9"},{"iden":"sample output 1","content":"28\n\nInitially, Takahashi has $30$ teeth, and Aoki performs six treatments.\n\n*   In the first treatment, hole $2$ is treated. There is a tooth in hole $2$, so it is removed.\n*   In the second treatment, hole $9$ is treated. There is a tooth in hole $9$, so it is removed.\n*   In the third treatment, hole $18$ is treated. There is a tooth in hole $18$, so it is removed.\n*   In the fourth treatment, hole $27$ is treated. There is a tooth in hole $27$, so it is removed.\n*   In the fifth treatment, hole $18$ is treated. There is no tooth in hole $18$, so a tooth is grown.\n*   In the sixth treatment, hole $9$ is treated. There is no tooth in hole $9$, so a tooth is grown.\n\nThe final count of teeth is $28$."},{"iden":"sample input 2","content":"1 7\n1 1 1 1 1 1 1"},{"iden":"sample output 2","content":"0"},{"iden":"sample input 3","content":"9 20\n9 5 1 2 2 2 8 9 2 1 6 2 6 5 8 7 8 5 9 8"},{"iden":"sample output 3","content":"5"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}