{"raw_statement":[{"iden":"background","content":"对应的选择、判断题：<https://ti.luogu.com.cn/problemset/1123>"},{"iden":"statement","content":"输入一个正整数 $n$，求形如：\n\n$1+(1+2)+(1+2+3)+(1+2+3+4)+ \\cdots  +(1+2+3+4+5+ \\cdots  +n)$ 的累计相加。"},{"iden":"input","content":"输入一个正整数 $n$。约定 $1<n \\le 100$。"},{"iden":"output","content":"输出累计相加的结果。"}],"translated_statement":null,"sample_group":[["3","10"],["4","20"],["10","220"]],"show_order":[],"formal_statement":null,"simple_statement":null,"has_page_source":false}