{"raw_statement":[{"iden":"problem statement","content":"There are $N$ squares numbered $1$ to $N$ from left to right. Each square has a character written on it, and Square $i$ has a letter $s_i$. Besides, there is initially one golem on each square.\nSnuke cast $Q$ spells to move the golems.\nThe $i$\\-th spell consisted of two characters $t_i$ and $d_i$, where $d_i$ is `L` or `R`. When Snuke cast this spell, for each square with the character $t_i$, all golems on that square moved to the square adjacent to the left if $d_i$ is `L`, and moved to the square adjacent to the right if $d_i$ is `R`.\nHowever, when a golem tried to move left from Square $1$ or move right from Square $N$, it disappeared.\nFind the number of golems remaining after Snuke cast the $Q$ spells."},{"iden":"constraints","content":"*   $1 \\leq N,Q \\leq 2 \\times 10^{5}$\n*   $|s| = N$\n*   $s_i$ and $t_i$ are uppercase English letters.\n*   $d_i$ is `L` or `R`."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$N$ $Q$\n$s$\n$t_1$ $d_1$\n$\\vdots$\n$t_{Q}$ $d_Q$"},{"iden":"sample input 1","content":"3 4\nABC\nA L\nB L\nB R\nA R"},{"iden":"sample output 1","content":"2\n\n*   Initially, there is one golem on each square.\n*   In the first spell, the golem on Square $1$ tries to move left and disappears.\n*   In the second spell, the golem on Square $2$ moves left.\n*   In the third spell, no golem moves.\n*   In the fourth spell, the golem on Square $1$ moves right.\n*   After the four spells are cast, there is one golem on Square $2$ and one golem on Square $3$, for a total of two golems remaining."},{"iden":"sample input 2","content":"8 3\nAABCBDBA\nA L\nB R\nA R"},{"iden":"sample output 2","content":"5\n\n*   After the three spells are cast, there is one golem on Square $2$, two golems on Square $4$ and two golems on Square $6$, for a total of five golems remaining.\n*   Note that a single spell may move multiple golems."},{"iden":"sample input 3","content":"10 15\nSNCZWRCEWB\nB R\nR R\nE R\nW R\nZ L\nS R\nQ L\nW L\nB R\nC L\nA L\nN L\nE R\nZ L\nS L"},{"iden":"sample output 3","content":"3"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}