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#include <stdio.h>

int func1() {
    void func2() { // nested function
       printf("func2() is called\n");
    }
    printf("func1() is called\n");
    func2();
    return 0;
}

int main() {
    func1();
    return 0;
}

The output is:
func1() is called
func2() is called