{"raw_statement":[{"iden":"problem statement","content":"There is a hotel with the following accommodation fee:\n\n*   $X$ yen (the currency of Japan) per night, for the first $K$ nights\n*   $Y$ yen per night, for the $(K+1)$\\-th and subsequent nights\n\nTak is staying at this hotel for $N$ consecutive nights. Find his total accommodation fee."},{"iden":"constraints","content":"*   $1 \\leq N, K \\leq 10000$\n*   $1 \\leq Y < X \\leq 10000$\n*   $N,\\,K,\\,X,\\,Y$ are integers."},{"iden":"input","content":"The input is given from Standard Input in the following format:\n\n$N$\n$K$\n$X$\n$Y$"},{"iden":"sample input 1","content":"5\n3\n10000\n9000"},{"iden":"sample output 1","content":"48000\n\nThe accommodation fee is as follows:\n\n*   $10000$ yen for the $1$\\-st night\n*   $10000$ yen for the $2$\\-nd night\n*   $10000$ yen for the $3$\\-rd night\n*   $9000$ yen for the $4$\\-th night\n*   $9000$ yen for the $5$\\-th night\n\nThus, the total is $48000$ yen."},{"iden":"sample input 2","content":"2\n3\n10000\n9000"},{"iden":"sample output 2","content":"20000"}],"translated_statement":null,"sample_group":[],"show_order":["default"],"formal_statement":null,"simple_statement":null,"has_page_source":true}