{"problem":{"name":"Sum of Fibonacci Sequence","description":{"content":"E869120 defined a sequence $a$ like this:   *   $a_1=a_2=1$, $a_{k+2}=a_{k+1}+a_k \\\\ (k \\\\ge 1)$    He also defined sequences $d_1, d_2, d_3, \\\\dots , d_n$, as the following recurrence relation :   ","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"s8pc_3_g"},"statements":[{"statement_type":"Markdown","content":"E869120 defined a sequence $a$ like this:  \n\n*   $a_1=a_2=1$, $a_{k+2}=a_{k+1}+a_k \\\\ (k \\\\ge 1)$\n\n  \nHe also defined sequences $d_1, d_2, d_3, \\\\dots , d_n$, as the following recurrence relation :  \n\n*   $d_{1, j} = a_j$\n*   $d_{i, j} = \\\\sum_{k = 1}^j d_{i - 1, k} \\\\ (i \\\\ge 2)$\n\n  \nYou are given integers $n$ and $m$. Please calculate the value of $d_{n, m}$.  \nSince the answer can be large number, print the answer modulo $998,244,353$.  \nCan you solve this problem???\n\n## Input\n\nThe input is given from standard input in the following format.  \n  \n\n> $n \\\\quad m$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"s8pc_3_g","tags":[],"sample_group":[["4 7","176\n\nThe sequence is following:  \n\n$d_{i, 1}$\n\n$d_{i, 2}$\n\n$d_{i, 3}$\n\n$d_{i, 4}$\n\n$d_{i, 5}$\n\n$d_{i, 6}$\n\n$d_{i, 7}$\n\n$d_1$\n\n1\n\n1\n\n2\n\n3\n\n5\n\n8\n\n13\n\n$d_2$\n\n1\n\n2\n\n4\n\n7\n\n12\n\n20\n\n33\n\n$d_3$\n\n1\n\n3\n\n7\n\n14\n\n26\n\n46\n\n79\n\n$d_4$\n\n1\n\n4\n\n11\n\n25\n\n51\n\n97\n\n176\n\n  \nAs a result, the answer is $d_{4, 7} = 176$."],["12 20","174174144"],["16 30","102292850\n\nYou can calculate that $d_{16, 30} = 1,193,004,294,685$.  \nPlease don't forget printing the answer mod $998,244,353$."]],"created_at":"2026-03-03 11:01:14"}}