C language program logic error?

Judging from the code itself and the running situation, the content of the executable program is not consistent with the published code (it may be that the modified code was run without recompiling after the code was modified, otherwise the code will not be compiled incorrectly now, for example, "op" was added at the end of line 2, and "existing 1 person donation" was not output). The modification suggestions are as follows: