{"trustable":false,"sections":[{"title":"题目描述","value":{"format":"MD","content":"一个C语言的for循环:\n```c\n for(int i\u003dA;i!\u003dB;i+\u003dC)st;\n```\n其中`i`表示变量,`A`、`B`和`C`分别表示初值、终值和步长,`st`表示循环体。\n要求计算当循环变量`i`运算在`k`位无符号整数体系下(运算值范围:0~2^k-1,此时,`i+\u003dc`溢出后截断),循环体`st`会执行多少次?\n"}},{"title":"输入格式","value":{"format":"MD","content":"输入每组数据包括4个整数`A`,`B`,`C`和`k`。"}},{"title":"输出格式","value":{"format":"MD","content":"对于每组数据,输出循环次数,如果永远不能结束,输出`FOREVER`。"}},{"title":"输入样例","value":{"format":"MD","content":"```\n1 3 2 4\n1 5 2 4\n1 2 4 3\n0 0 0 0\n```"}},{"title":"输出样例","value":{"format":"MD","content":"```\n1\n2\nFOREVER\n```"}},{"title":"数据范围","value":{"format":"MD","content":"1≤k≤32。\n 0≤A, B, C≤2^k。"}}]}