python代码RE了,写了一份同样的C++的代码A了.求大佬帮忙分析一下python代码哪里有问题

a = eval(input())
n = eval(input())
tot = eval(input())
x = eval(input())


def fib(x):
    if x == 1:
        return 1
    if x == 2:
        return 1
    return fib(x - 1) + fib(x - 2)


def findb(x):
    if x <= 3:
        return 0
    ans = 0
    for i in range(1, x - 2):
        ans += fib(i)
    return ans


def finda(x):
    if x <= 4:
        return 2
    ans = 2
    for i in range(1, x - 3):
        ans += fib(i)
    return ans 


b = (tot - finda(n - 1) * a) / findb(n - 1)


print(finda(x) * a + findb(x) * b)

#include <cstdio>
using namespace std;

int a, b, n, x, tot;

int fib(int x) {
    if(x == 1 or x == 2)
        return 1;
    return fib(x - 1) + fib(x - 2);
}

int finda(int x) {
    if(x <= 4)
        return 2;
    int ans = 2;
    for(int i = 1; i <= x - 4; i++)
        ans += fib(i);
    return ans;
}

int findb(int x) {
    if(x <= 3)
        return 0;
    int ans = 0;
    for(int i = 1; i <= x - 3; i++)
        ans += fib(i);
    return ans;
}

int main() {
    scanf("%d%d%d%d", &a, &n, &tot, &x);
    b = (tot - finda(n - 1) * a) / findb(n -1);
    printf("%d", finda(x) * a + findb(x) * b);
    return 0;
}