error: expected ')' before '&' token

[「已注销」]

编译一个“约分分数为最简分式”程序时遇到 error: expected ')' before '&' token
代码如下：

#include <stdio.h>

/* prototype */
void reduce(int numerator, int denominator,
            int *reduced_numerator, int *reduced_denominator);

int main(void)
{
    int m, n, reduced_m, reduced_n;

    printf("Enter a fraction: ");
    scanf("%d/%d", &m, &n);

    void reduce(m, n, &reduced_m, &reduced_n);    //错误显示在这行

    printf("In lowest terms: %d/%d\n", reduced_m, reduced_n);

    return 0;
}

void reduce(int numerator, int denominator,
            int *reduced_numerator, int *reduced_denominator)
{
    int mod, m, n;

    m = numerator;
    n = denominator;

    while (n != 0) {
        mod = m % n;
        m = n;
        n = mod;
    }

    *reduced_numerator = numerator / m;
    *reduced_denominator = denominator / m;
}

[爱爬山的IT小小鸟]

第14行， 函数调用，去掉前面的函数返回值类型void

[「已注销」]

写函数原型写疯了，谢谢！