{"raw_statement":[{"iden":"problem statement","content":"You are given integers $L,R$ ($L < R$).\nSnuke is looking for a pair of integers $(x,y)$ that satisfy both of the conditions below.\n\n*   $L \\leq x < y \\leq R$\n*   $\\gcd(x,y)=1$\n\nFind the maximum possible value of $(y-x)$ in a pair that satisfies the conditions. It can be proved that at least one such pair exists under the Constraints."},{"iden":"constraints","content":"*   $1 \\leq L < R \\leq 10^{18}$\n*   All values in input are integers."},{"iden":"input","content":"Input is given from Standard Input in the following format:\n\n$L$ $R$"},{"iden":"sample input 1","content":"2 4"},{"iden":"sample output 1","content":"1\n\nFor $(x,y)=(2,4)$, we have $\\gcd(x,y)=2$, which violates the condition. For $(x,y)=(2,3)$, the conditions are satisfied. Here, the value of $(y-x)$ is $1$. There is no such pair with a greater value of $(y-x)$, so the answer is $1$."},{"iden":"sample input 2","content":"14 21"},{"iden":"sample output 2","content":"5"},{"iden":"sample input 3","content":"1 100"},{"iden":"sample output 3","content":"99"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}